rules/falco_rules.yaml

# SPDX-License-Identifier: Apache-2.0
#
# Copyright (C) 2023 The Falco Authors.
#
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

# Information about rules tags and fields can be found here: https://falco.org/docs/rules/#tags-for-current-falco-ruleset
# The initial item in the `tags` fields reflects the maturity level of the rules introduced upon the proposal https://github.com/falcosecurity/rules/blob/main/proposals/20230605-rules-adoption-management-maturity-framework.md
# `tags` fields also include information about the type of workload inspection (host and/or container), and Mitre Attack killchain phases and Mitre TTP code(s)
# Mitre Attack References:
# [1] https://attack.mitre.org/tactics/enterprise/
# [2] https://raw.githubusercontent.com/mitre/cti/master/enterprise-attack/enterprise-attack.json

# Starting with version 8, the Falco engine supports exceptions.
# However the Falco rules file does not use them by default.
- required_engine_version: 0.31.0

# Currently disabled as read/write are ignored syscalls. The nearly
# similar open_write/open_read check for files being opened for
# reading/writing.
# - macro: write
#   condition: (syscall.type=write and fd.type in (file, directory))
# - macro: read
#   condition: (syscall.type=read and evt.dir=> and fd.type in (file, directory))

- macro: open_write
  condition: (evt.type in (open,openat,openat2) and evt.is_open_write=true and fd.typechar='f' and fd.num>=0)

- macro: open_read
  condition: (evt.type in (open,openat,openat2) and evt.is_open_read=true and fd.typechar='f' and fd.num>=0)

# Failed file open attempts, useful to detect threat actors making mistakes
# https://man7.org/linux/man-pages/man3/errno.3.html
# evt.res=ENOENT - No such file or directory
# evt.res=EACCESS - Permission denied
- macro: open_file_failed
  condition: (evt.type in (open,openat,openat2) and fd.typechar='f' and fd.num=-1 and evt.res startswith E)

# This macro `never_true` is used as placeholder for tuning negative logical sub-expressions, for example
# - macro: allowed_ssh_hosts
#   condition: (never_true)
# can be used in a rules' expression with double negation `and not allowed_ssh_hosts` which effectively evaluates
# to true and does nothing, the perfect empty template for `logical` cases as opposed to list templates.
# When tuning the rule you can override the macro with something useful, e.g.
# - macro: allowed_ssh_hosts
#   condition: (evt.hostname contains xyz)
- macro: never_true
  condition: (evt.num=0)

# This macro `always_true` is the flip side of the macro `never_true` and currently is commented out as
# it is not used. You can use it as placeholder for a positive logical sub-expression tuning template
# macro, e.g. `and custom_procs`, where
# - macro: custom_procs
#   condition: (always_true)
# later you can customize, override the macros to something like
# - macro: custom_procs
#   condition: (proc.name in (custom1, custom2, custom3))
# - macro: always_true
#   condition: (evt.num>=0)

# In some cases, such as dropped system call events, information about
# the process name may be missing. For some rules that really depend
# on the identity of the process performing an action such as opening
# a file, etc., we require that the process name be known.
# TODO: At the moment we keep the `N/A` variant for compatibility with old scap-files
- macro: proc_name_exists
  condition: (not proc.name in ("<NA>","N/A"))

- macro: spawned_process
  condition: (evt.type in (execve, execveat) and evt.dir=<)

- macro: create_symlink
  condition: (evt.type in (symlink, symlinkat) and evt.dir=<)

- macro: create_hardlink
  condition: (evt.type in (link, linkat) and evt.dir=<)

- macro: kernel_module_load
  condition: (evt.type in (init_module, finit_module) and evt.dir=<)

- macro: dup
  condition: (evt.type in (dup, dup2, dup3) and evt.dir=<)

# File categories
- macro: etc_dir
  condition: (fd.name startswith /etc/)

- list: shell_binaries
  items: [ash, bash, csh, ksh, sh, tcsh, zsh, dash]

- macro: shell_procs
  condition: (proc.name in (shell_binaries))

# dpkg -L login | grep bin | xargs ls -ld | grep -v '^d' | awk '{print $9}' | xargs -L 1 basename | tr "\\n" ","
- list: login_binaries
  items: [
    login, systemd, '"(systemd)"', systemd-logind, su,
    nologin, faillog, lastlog, newgrp, sg
    ]

# dpkg -L passwd | grep bin | xargs ls -ld | grep -v '^d' | awk '{print $9}' | xargs -L 1 basename | tr "\\n" ","
- list: passwd_binaries
  items: [
    shadowconfig, grpck, pwunconv, grpconv, pwck,
    groupmod, vipw, pwconv, useradd, newusers, cppw, chpasswd, usermod,
    groupadd, groupdel, grpunconv, chgpasswd, userdel, chage, chsh,
    gpasswd, chfn, expiry, passwd, vigr, cpgr, adduser, addgroup, deluser, delgroup
    ]

# repoquery -l shadow-utils | grep bin | xargs ls -ld | grep -v '^d' |
#     awk '{print $9}' | xargs -L 1 basename | tr "\\n" ","
- list: shadowutils_binaries
  items: [
    chage, gpasswd, lastlog, newgrp, sg, adduser, deluser, chpasswd,
    groupadd, groupdel, addgroup, delgroup, groupmems, groupmod, grpck, grpconv, grpunconv,
    newusers, pwck, pwconv, pwunconv, useradd, userdel, usermod, vigr, vipw, unix_chkpwd
    ]

- list: http_server_binaries
  items: [nginx, httpd, httpd-foregroun, lighttpd, apache, apache2]

- list: db_server_binaries
  items: [mysqld, postgres, sqlplus]

- list: postgres_mgmt_binaries
  items: [pg_dumpall, pg_ctl, pg_lsclusters, pg_ctlcluster]

- list: nosql_server_binaries
  items: [couchdb, memcached, redis-server, rabbitmq-server, mongod]

- list: gitlab_binaries
  items: [gitlab-shell, gitlab-mon, gitlab-runner-b, git]

- macro: server_procs
  condition: (proc.name in (http_server_binaries, db_server_binaries, docker_binaries, sshd))

# The explicit quotes are needed to avoid the - characters being
# interpreted by the filter expression.
- list: rpm_binaries
  items: [dnf, dnf-automatic, rpm, rpmkey, yum, '"75-system-updat"', rhsmcertd-worke, rhsmcertd, subscription-ma,
          repoquery, rpmkeys, rpmq, yum-cron, yum-config-mana, yum-debug-dump,
          abrt-action-sav, rpmdb_stat, microdnf, rhn_check, yumdb]

- list: deb_binaries
  items: [dpkg, dpkg-preconfigu, dpkg-reconfigur, dpkg-divert, apt, apt-get, aptitude,
    frontend, preinst, add-apt-reposit, apt-auto-remova, apt-key,
    apt-listchanges, unattended-upgr, apt-add-reposit, apt-cache, apt.systemd.dai
    ]
- list: python_package_managers
  items: [pip, pip3, conda]

# The truncated dpkg-preconfigu is intentional, process names are
# truncated at the falcosecurity-libs level.
- list: package_mgmt_binaries
  items: [rpm_binaries, deb_binaries, update-alternat, gem, npm, python_package_managers, sane-utils.post, alternatives, chef-client, apk, snapd]

- macro: run_by_package_mgmt_binaries
  condition: (proc.aname in (package_mgmt_binaries, needrestart))

# A canonical set of processes that run other programs with different
# privileges or as a different user.
- list: userexec_binaries
  items: [sudo, su, suexec, critical-stack, dzdo]

- list: user_mgmt_binaries
  items: [login_binaries, passwd_binaries, shadowutils_binaries]

- list: hids_binaries
  items: [aide, aide.wrapper, update-aide.con, logcheck, syslog-summary, osqueryd, ossec-syscheckd]

- list: vpn_binaries
  items: [openvpn]

- list: nomachine_binaries
  items: [nxexec, nxnode.bin, nxserver.bin, nxclient.bin]

- list: mail_binaries
  items: [
    sendmail, sendmail-msp, postfix, procmail, exim4,
    pickup, showq, mailq, dovecot, imap-login, imap,
    mailmng-core, pop3-login, dovecot-lda, pop3
    ]

- list: mail_config_binaries
  items: [
    update_conf, parse_mc, makemap_hash, newaliases, update_mk, update_tlsm4,
    update_db, update_mc, ssmtp.postinst, mailq, postalias, postfix.config.,
    postfix.config, postfix-script, postconf
    ]

- list: sensitive_file_names
  items: [/etc/shadow, /etc/sudoers, /etc/pam.conf, /etc/security/pwquality.conf]

- list: sensitive_directory_names
  items: [/, /etc, /etc/, /root, /root/]

- macro: sensitive_files
  condition: >
    (fd.name in (sensitive_file_names) or
      fd.directory in (/etc/sudoers.d, /etc/pam.d))

# Indicates that the process is new. Currently detected using time
# since process was started, using a threshold of 5 seconds.
- macro: proc_is_new
  condition: (proc.duration <= 5000000000)

# Use this to test whether the event occurred within a container.
# When displaying container information in the output field, use
# %container.info, without any leading term (file=%fd.name
# %container.info user=%user.name user_loginuid=%user.loginuid, and not file=%fd.name
# container=%container.info user=%user.name user_loginuid=%user.loginuid). The output will change
# based on the context and whether or not -pk/-pm/-pc was specified on
# the command line.
- macro: container
  condition: (container.id != host)

- macro: interactive
  condition: >
    ((proc.aname=sshd and proc.name != sshd) or
    proc.name=systemd-logind or proc.name=login)

- list: cron_binaries
  items: [anacron, cron, crond, crontab]

# https://github.com/liske/needrestart
- list: needrestart_binaries
  items: [needrestart, 10-dpkg, 20-rpm, 30-pacman]

# Possible scripts run by sshkit
- list: sshkit_script_binaries
  items: [10_etc_sudoers., 10_passwd_group]

# System users that should never log into a system. Consider adding your own
# service users (e.g. 'apache' or 'mysqld') here.
- macro: system_users
  condition: (user.name in (bin, daemon, games, lp, mail, nobody, sshd, sync, uucp, www-data))

- macro: ansible_running_python
  condition: (proc.name in (python, pypy, python3) and proc.cmdline contains ansible)

# Qualys seems to run a variety of shell subprocesses, at various
# levels. This checks at a few levels without the cost of a full
# proc.aname, which traverses the full parent hierarchy.
- macro: run_by_qualys
  condition: >
    (proc.pname=qualys-cloud-ag or
     proc.aname[2]=qualys-cloud-ag or
     proc.aname[3]=qualys-cloud-ag or
     proc.aname[4]=qualys-cloud-ag)

- macro: run_by_google_accounts_daemon
  condition: >
    (proc.aname[1] startswith google_accounts or
     proc.aname[2] startswith google_accounts or
     proc.aname[3] startswith google_accounts)

# Chef is similar.
- macro: run_by_chef
  condition: (proc.aname[2]=chef_command_wr or proc.aname[3]=chef_command_wr or
              proc.aname[2]=chef-client or proc.aname[3]=chef-client or
              proc.name=chef-client)

# Also handles running semi-indirectly via scl
- macro: run_by_foreman
  condition: >
    (user.name=foreman and
     ((proc.pname in (rake, ruby, scl) and proc.aname[5] in (tfm-rake,tfm-ruby)) or
     (proc.pname=scl and proc.aname[2] in (tfm-rake,tfm-ruby))))

- macro: python_mesos_marathon_scripting
  condition: (proc.pcmdline startswith "python3 /marathon-lb/marathon_lb.py")

- macro: splunk_running_forwarder
  condition: (proc.pname=splunkd and proc.cmdline startswith "sh -c /opt/splunkforwarder")

- macro: perl_running_plesk
  condition: (proc.cmdline startswith "perl /opt/psa/admin/bin/plesk_agent_manager" or
              proc.pcmdline startswith "perl /opt/psa/admin/bin/plesk_agent_manager")

- macro: perl_running_updmap
  condition: (proc.cmdline startswith "perl /usr/bin/updmap")

- macro: perl_running_centrifydc
  condition: (proc.cmdline startswith "perl /usr/share/centrifydc")

- macro: runuser_reading_pam
  condition: (proc.name=runuser and fd.directory=/etc/pam.d)

# CIS Linux Benchmark program
- macro: linux_bench_reading_etc_shadow
  condition: ((proc.aname[2]=linux-bench and
               proc.name in (awk,cut,grep)) and
              (fd.name=/etc/shadow or
               fd.directory=/etc/pam.d))

- macro: veritas_driver_script
  condition: (proc.cmdline startswith "perl /opt/VRTSsfmh/bin/mh_driver.pl")

- macro: user_ssh_directory
  condition: (fd.name contains '/.ssh/' and fd.name glob '/home/*/.ssh/*')

- macro: directory_traversal
  condition: (fd.nameraw contains '../' and fd.nameraw glob '*../*../*')

# ******************************************************************************
# * "Directory traversal monitored file read" requires FALCO_ENGINE_VERSION 13 *
# ******************************************************************************
- rule: Directory traversal monitored file read
  desc: >
    Web applications can be vulnerable to directory traversal attacks that allow accessing files outside of the web app's root directory 
    (e.g. Arbitrary File Read bugs). System directories like /etc are typically accessed via absolute paths. Access patterns outside of this 
    (here path traversal) can be regarded as suspicious. This rule includes failed file open attempts.
  condition: > 
    (open_read or open_file_failed) 
    and (etc_dir or user_ssh_directory or 
         fd.name startswith /root/.ssh or 
         fd.name contains "id_rsa") 
    and directory_traversal 
    and not proc.pname in (shell_binaries)
  enabled: true
  output: Read monitored file via directory traversal (file=%fd.name fileraw=%fd.nameraw gparent=%proc.aname[2] ggparent=%proc.aname[3] gggparent=%proc.aname[4] evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: WARNING
  tags: [maturity_stable, host, container, filesystem, mitre_credential_access, T1555]

- macro: cmp_cp_by_passwd
  condition: (proc.name in (cmp, cp) and proc.pname in (passwd, run-parts))

- macro: user_known_read_sensitive_files_activities
  condition: (never_true)

- rule: Read sensitive file trusted after startup
  desc: >
    An attempt to read any sensitive file (e.g. files containing user/password/authentication
    information) by a trusted program after startup. Trusted programs might read these files
    at startup to load initial state, but not afterwards. Can be customized as needed.
    In modern containerized cloud infrastructures, accessing traditional Linux sensitive files 
    might be less relevant, yet it remains valuable for baseline detections. While we provide additional 
    rules for SSH or cloud vendor-specific credentials, you can significantly enhance your security 
    program by crafting custom rules for critical application credentials unique to your environment.
  condition: > 
    open_read 
    and sensitive_files 
    and server_procs 
    and not proc_is_new 
    and proc.name!="sshd" 
    and not user_known_read_sensitive_files_activities
  output: Sensitive file opened for reading by trusted program after startup (file=%fd.name pcmdline=%proc.pcmdline gparent=%proc.aname[2] ggparent=%proc.aname[3] gggparent=%proc.aname[4] evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: WARNING
  tags: [maturity_stable, host, container, filesystem, mitre_credential_access, T1555]

- list: read_sensitive_file_binaries
  items: [
    iptables, ps, lsb_release, check-new-relea, dumpe2fs, accounts-daemon, sshd,
    vsftpd, systemd, mysql_install_d, psql, screen, debconf-show, sa-update,
    pam-auth-update, pam-config, /usr/sbin/spamd, polkit-agent-he, lsattr, file, sosreport,
    scxcimservera, adclient, rtvscand, cockpit-session, userhelper, ossec-syscheckd
    ]

# Add conditions to this macro (probably in a separate file,
# overwriting this macro) to allow for specific combinations of
# programs accessing sensitive files.
# fluentd_writing_conf_files is a good example to follow, as it
# specifies both the program doing the writing as well as the specific
# files it is allowed to modify.
#
# In this file, it just takes one of the macros in the base rule
# and repeats it.
- macro: user_read_sensitive_file_conditions
  condition: cmp_cp_by_passwd

- list: read_sensitive_file_images
  items: []

- macro: user_read_sensitive_file_containers
  condition: (container and container.image.repository in (read_sensitive_file_images))

# This macro detects man-db postinst, see https://salsa.debian.org/debian/man-db/-/blob/master/debian/postinst
# The rule "Read sensitive file untrusted" use this macro to avoid FPs.
- macro: mandb_postinst
  condition: >
    (proc.name=perl and proc.args startswith "-e" and
    proc.args contains "@pwd = getpwnam(" and
    proc.args contains "exec " and
    proc.args contains "/usr/bin/mandb")

- rule: Read sensitive file untrusted
  desc: >
    An attempt to read any sensitive file (e.g. files containing user/password/authentication
    information). Exceptions are made for known trusted programs. Can be customized as needed.
    In modern containerized cloud infrastructures, accessing traditional Linux sensitive files 
    might be less relevant, yet it remains valuable for baseline detections. While we provide additional 
    rules for SSH or cloud vendor-specific credentials, you can significantly enhance your security 
    program by crafting custom rules for critical application credentials unique to your environment.
  condition: >
    open_read
    and sensitive_files
    and proc_name_exists
    and not proc.name in (user_mgmt_binaries, userexec_binaries, package_mgmt_binaries,
     cron_binaries, read_sensitive_file_binaries, shell_binaries, hids_binaries,
     vpn_binaries, mail_config_binaries, nomachine_binaries, sshkit_script_binaries,
     in.proftpd, mandb, salt-call, salt-minion, postgres_mgmt_binaries,
     google_oslogin_
     )
    and not cmp_cp_by_passwd
    and not ansible_running_python
    and not run_by_qualys
    and not run_by_chef
    and not run_by_google_accounts_daemon
    and not user_read_sensitive_file_conditions
    and not mandb_postinst
    and not perl_running_plesk
    and not perl_running_updmap
    and not veritas_driver_script
    and not perl_running_centrifydc
    and not runuser_reading_pam
    and not linux_bench_reading_etc_shadow
    and not user_known_read_sensitive_files_activities
    and not user_read_sensitive_file_containers
  output: Sensitive file opened for reading by non-trusted program (file=%fd.name gparent=%proc.aname[2] ggparent=%proc.aname[3] gggparent=%proc.aname[4] evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: WARNING
  tags: [maturity_stable, host, container, filesystem, mitre_credential_access, T1555]

- macro: postgres_running_wal_e
  condition: (proc.pname=postgres and (proc.cmdline startswith "sh -c envdir /etc/wal-e.d/env /usr/local/bin/wal-e" or proc.cmdline startswith "sh -c envdir \"/run/etc/wal-e.d/env\" wal-g wal-push"))

- macro: redis_running_prepost_scripts
  condition: (proc.aname[2]=redis-server and (proc.cmdline contains "redis-server.post-up.d" or proc.cmdline contains "redis-server.pre-up.d"))

- macro: rabbitmq_running_scripts
  condition: >
    (proc.pname=beam.smp and
    (proc.cmdline startswith "sh -c exec ps" or
     proc.cmdline startswith "sh -c exec inet_gethost" or
     proc.cmdline= "sh -s unix:cmd" or
     proc.cmdline= "sh -c exec /bin/sh -s unix:cmd 2>&1"))

- macro: rabbitmqctl_running_scripts
  condition: (proc.aname[2]=rabbitmqctl and proc.cmdline startswith "sh -c ")

- macro: run_by_appdynamics
  condition: (proc.pexe endswith java and proc.pcmdline contains " -jar -Dappdynamics")

# The binaries in this list and their descendents are *not* allowed
# spawn shells. This includes the binaries spawning shells directly as
# well as indirectly. For example, apache -> php/perl for
# mod_{php,perl} -> some shell is also not allowed, because the shell
# has apache as an ancestor.
- list: protected_shell_spawning_binaries
  items: [
    http_server_binaries, db_server_binaries, nosql_server_binaries, mail_binaries,
    fluentd, flanneld, splunkd, consul, smbd, runsv, PM2
    ]

- macro: parent_java_running_zookeeper
  condition: (proc.pexe endswith java and proc.pcmdline contains org.apache.zookeeper.server)

- macro: parent_java_running_kafka
  condition: (proc.pexe endswith java and proc.pcmdline contains kafka.Kafka)

- macro: parent_java_running_elasticsearch
  condition: (proc.pexe endswith java and proc.pcmdline contains org.elasticsearch.bootstrap.Elasticsearch)

- macro: parent_java_running_activemq
  condition: (proc.pexe endswith java and proc.pcmdline contains activemq.jar)

- macro: parent_java_running_cassandra
  condition: (proc.pexe endswith java and (proc.pcmdline contains "-Dcassandra.config.loader" or proc.pcmdline contains org.apache.cassandra.service.CassandraDaemon))

- macro: parent_java_running_jboss_wildfly
  condition: (proc.pexe endswith java and proc.pcmdline contains org.jboss)

- macro: parent_java_running_glassfish
  condition: (proc.pexe endswith java and proc.pcmdline contains com.sun.enterprise.glassfish)

- macro: parent_java_running_hadoop
  condition: (proc.pexe endswith java and proc.pcmdline contains org.apache.hadoop)

- macro: parent_java_running_datastax
  condition: (proc.pexe endswith java and proc.pcmdline contains com.datastax)

- macro: nginx_starting_nginx
  condition: (proc.pname=nginx and proc.cmdline contains "/usr/sbin/nginx -c /etc/nginx/nginx.conf")

- macro: nginx_running_aws_s3_cp
  condition: (proc.pname=nginx and proc.cmdline startswith "sh -c /usr/local/bin/aws s3 cp")

- macro: consul_running_net_scripts
  condition: (proc.pname=consul and (proc.cmdline startswith "sh -c curl" or proc.cmdline startswith "sh -c nc"))

- macro: consul_running_alert_checks
  condition: (proc.pname=consul and proc.cmdline startswith "sh -c /bin/consul-alerts")

- macro: serf_script
  condition: (proc.cmdline startswith "sh -c serf")

- macro: check_process_status
  condition: (proc.cmdline startswith "sh -c kill -0 ")

# In some cases, you may want to consider node processes run directly
# in containers as protected shell spawners. Examples include using
# pm2-docker or pm2 start some-app.js --no-daemon-mode as the direct
# entrypoint of the container, and when the node app is a long-lived
# server using something like express.
#
# However, there are other uses of node related to build pipelines for
# which node is not really a server but instead a general scripting
# tool. In these cases, shells are very likely and in these cases you
# don't want to consider node processes protected shell spawners.
#
# We have to choose one of these cases, so we consider node processes
# as unprotected by default. If you want to consider any node process
# run in a container as a protected shell spawner, override the below
# macro to remove the "never_true" clause, which allows it to take effect.
- macro: possibly_node_in_container
  condition: (never_true and (proc.pname=node and proc.aname[3]=docker-containe))

# Similarly, you may want to consider any shell spawned by apache
# tomcat as suspect. The famous apache struts attack (CVE-2017-5638)
# could be exploited to do things like spawn shells.
#
# However, many applications *do* use tomcat to run arbitrary shells,
# as a part of build pipelines, etc.
#
# Like for node, we make this case opt-in.
- macro: possibly_parent_java_running_tomcat
  condition: (never_true and proc.pexe endswith java and proc.pcmdline contains org.apache.catalina.startup.Bootstrap)

- macro: protected_shell_spawner
  condition: >
    (proc.aname in (protected_shell_spawning_binaries)
    or parent_java_running_zookeeper
    or parent_java_running_kafka
    or parent_java_running_elasticsearch
    or parent_java_running_activemq
    or parent_java_running_cassandra
    or parent_java_running_jboss_wildfly
    or parent_java_running_glassfish
    or parent_java_running_hadoop
    or parent_java_running_datastax
    or possibly_parent_java_running_tomcat
    or possibly_node_in_container)

- list: mesos_shell_binaries
  items: [mesos-docker-ex, mesos-slave, mesos-health-ch]

# Note that runsv is both in protected_shell_spawner and the
# exclusions by pname. This means that runsv can itself spawn shells
# (the ./run and ./finish scripts), but the processes runsv can not
# spawn shells.
- rule: Run shell untrusted
  desc: > 
    An attempt to spawn a shell below a non-shell application. The non-shell applications that are monitored are 
    defined in the protected_shell_spawner macro, with protected_shell_spawning_binaries being the list you can 
    easily customize. For Java parent processes, please note that Java often has a custom process name. Therefore, 
    rely more on proc.exe to define Java applications. This rule can be noisier, as you can see in the exhaustive 
    existing tuning. However, given it is very behavior-driven and broad, it is universally relevant to catch 
    general Remote Code Execution (RCE). Allocate time to tune this rule for your use cases and reduce noise. 
    Tuning suggestions include looking at the duration of the parent process (proc.ppid.duration) to define your 
    long-running app processes. Checking for newer fields such as proc.vpgid.name and proc.vpgid.exe instead of the 
    direct parent process being a non-shell application could make the rule more robust.
  condition: >
    spawned_process
    and shell_procs
    and proc.pname exists
    and protected_shell_spawner
    and not proc.pname in (shell_binaries, gitlab_binaries, cron_binaries, user_known_shell_spawn_binaries,
                           needrestart_binaries,
                           mesos_shell_binaries,
                           erl_child_setup, exechealthz,
                           PM2, PassengerWatchd, c_rehash, svlogd, logrotate, hhvm, serf,
                           lb-controller, nvidia-installe, runsv, statsite, erlexec, calico-node,
                           "puma reactor")
    and not proc.cmdline in (known_shell_spawn_cmdlines)
    and not proc.aname in (unicorn_launche)
    and not consul_running_net_scripts
    and not consul_running_alert_checks
    and not nginx_starting_nginx
    and not nginx_running_aws_s3_cp
    and not run_by_package_mgmt_binaries
    and not serf_script
    and not check_process_status
    and not run_by_foreman
    and not python_mesos_marathon_scripting
    and not splunk_running_forwarder
    and not postgres_running_wal_e
    and not redis_running_prepost_scripts
    and not rabbitmq_running_scripts
    and not rabbitmqctl_running_scripts
    and not run_by_appdynamics
    and not user_shell_container_exclusions
  output: Shell spawned by untrusted binary (parent_exe=%proc.pexe parent_exepath=%proc.pexepath pcmdline=%proc.pcmdline gparent=%proc.aname[2] ggparent=%proc.aname[3] aname[4]=%proc.aname[4] aname[5]=%proc.aname[5] aname[6]=%proc.aname[6] aname[7]=%proc.aname[7] evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: NOTICE
  tags: [maturity_stable, host, container, process, shell, mitre_execution, T1059.004]

# These images are allowed both to run with --privileged and to mount
# sensitive paths from the host filesystem.
#
# NOTE: This list is only provided for backwards compatibility with
# older local falco rules files that may have been appending to
# trusted_images. To make customizations, it's better to add images to
# either privileged_images or falco_sensitive_mount_images.
- list: trusted_images
  items: []

- list: sematext_images
  items: [docker.io/sematext/sematext-agent-docker, docker.io/sematext/agent, docker.io/sematext/logagent,
          registry.access.redhat.com/sematext/sematext-agent-docker,
          registry.access.redhat.com/sematext/agent,
          registry.access.redhat.com/sematext/logagent]

# Falco containers
- list: falco_containers
  items:
    - falcosecurity/falco
    - docker.io/falcosecurity/falco
    - public.ecr.aws/falcosecurity/falco

# Falco no driver containers
- list: falco_no_driver_containers
  items:
    - falcosecurity/falco-no-driver
    - docker.io/falcosecurity/falco-no-driver
    - public.ecr.aws/falcosecurity/falco-no-driver

# These container images are allowed to run with --privileged and full set of capabilities
- list: falco_privileged_images
  items: [
    falco_containers,
    docker.io/calico/node,
    calico/node,
    docker.io/cloudnativelabs/kube-router,
    docker.io/docker/ucp-agent,
    docker.io/mesosphere/mesos-slave,
    docker.io/rook/toolbox,
    docker.io/sysdig/sysdig,
    gcr.io/google_containers/kube-proxy,
    gcr.io/google-containers/startup-script,
    gcr.io/projectcalico-org/node,
    gke.gcr.io/kube-proxy,
    gke.gcr.io/gke-metadata-server,
    gke.gcr.io/netd-amd64,
    gke.gcr.io/watcher-daemonset,
    gcr.io/google-containers/prometheus-to-sd,
    registry.k8s.io/ip-masq-agent-amd64,
    registry.k8s.io/kube-proxy,
    registry.k8s.io/prometheus-to-sd,
    quay.io/calico/node,
    sysdig/sysdig,
    sematext_images,
    registry.k8s.io/dns/k8s-dns-node-cache,
    mcr.microsoft.com/oss/kubernetes/kube-proxy
  ]

# The steps libcontainer performs to set up the root program for a container are:
# - clone + exec self to a program runc:[0:PARENT]
# - clone a program runc:[1:CHILD] which sets up all the namespaces
# - clone a second program runc:[2:INIT] + exec to the root program.
#   The parent of runc:[2:INIT] is runc:0:PARENT]
# As soon as 1:CHILD is created, 0:PARENT exits, so there's a race
#   where at the time 2:INIT execs the root program, 0:PARENT might have
#   already exited, or might still be around. So we handle both.
# We also let runc:[1:CHILD] count as the parent process, which can occur
# when we lose events and lose track of state.
- macro: container_entrypoint
  condition: (not proc.pname exists or proc.pname in (runc:[0:PARENT], runc:[1:CHILD], runc, docker-runc, exe, docker-runc-cur, containerd-shim, systemd, crio))

- macro: user_known_system_user_login
  condition: (never_true)

# Anything run interactively by root
# - condition: evt.type != switch and user.name = root and proc.name != sshd and interactive
#  output: "Interactive root (%user.name %proc.name %evt.dir %evt.type %evt.args %fd.name)"
#  priority: WARNING
- rule: System user interactive
  desc: > 
    System (e.g. non-login) users spawning new processes. Can add custom service users (e.g. apache or mysqld).
    'Interactive' is defined as new processes as descendants of an ssh session or login process. Consider further tuning 
    by only looking at processes in a terminal / tty (proc.tty != 0). A newer field proc.is_vpgid_leader could be of help 
    to distinguish if the process was "directly" executed, for instance, in a tty, or executed as a descendant process in the 
    same process group, which, for example, is the case when subprocesses are spawned from a script. Consider this rule 
    as a great template rule to monitor interactive accesses to your systems more broadly. However, such a custom rule would be 
    unique to your environment. The rule "Terminal shell in container" that fires when using "kubectl exec" is more Kubernetes 
    relevant, whereas this one could be more interesting for the underlying host.
  condition: > 
    spawned_process 
    and system_users 
    and interactive 
    and not user_known_system_user_login
  output: System user ran an interactive command (evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: INFO
  tags: [maturity_stable, host, container, users, mitre_execution, T1059, NIST_800-53_AC-2]

# In some cases, a shell is expected to be run in a container. For example, configuration
# management software may do this, which is expected.
- macro: user_expected_terminal_shell_in_container_conditions
  condition: (never_true)

- rule: Terminal shell in container
  desc: >
    A shell was used as the entrypoint/exec point into a container with an attached terminal. Parent process may have 
    legitimately already exited and be null (read container_entrypoint macro). Common when using "kubectl exec" in Kubernetes. 
    Correlate with k8saudit exec logs if possible to find user or serviceaccount token used (fuzzy correlation by namespace and pod name). 
    Rather than considering it a standalone rule, it may be best used as generic auditing rule while examining other triggered 
    rules in this container/tty.
  condition: >
    spawned_process 
    and container
    and shell_procs 
    and proc.tty != 0
    and container_entrypoint
    and not user_expected_terminal_shell_in_container_conditions
  output: A shell was spawned in a container with an attached terminal (evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: NOTICE
  tags: [maturity_stable, container, shell, mitre_execution, T1059]

# For some container types (mesos), there isn't a container image to
# work with, and the container name is autogenerated, so there isn't
# any stable aspect of the software to work with. In this case, we
# fall back to allowing certain command lines.
- list: known_shell_spawn_cmdlines
  items: [
    '"sh -c uname -p 2> /dev/null"',
    '"sh -c uname -s 2>&1"',
    '"sh -c uname -r 2>&1"',
    '"sh -c uname -v 2>&1"',
    '"sh -c uname -a 2>&1"',
    '"sh -c ruby -v 2>&1"',
    '"sh -c getconf CLK_TCK"',
    '"sh -c getconf PAGESIZE"',
    '"sh -c LC_ALL=C LANG=C /sbin/ldconfig -p 2>/dev/null"',
    '"sh -c LANG=C /sbin/ldconfig -p 2>/dev/null"',
    '"sh -c /sbin/ldconfig -p 2>/dev/null"',
    '"sh -c stty -a 2>/dev/null"',
    '"sh -c stty -a < /dev/tty"',
    '"sh -c stty -g < /dev/tty"',
    '"sh -c node index.js"',
    '"sh -c node index"',
    '"sh -c node ./src/start.js"',
    '"sh -c node app.js"',
    '"sh -c node -e \"require(''nan'')\""',
    '"sh -c node -e \"require(''nan'')\")"',
    '"sh -c node $NODE_DEBUG_OPTION index.js "',
    '"sh -c crontab -l 2"',
    '"sh -c lsb_release -a"',
    '"sh -c lsb_release -is 2>/dev/null"',
    '"sh -c whoami"',
    '"sh -c node_modules/.bin/bower-installer"',
    '"sh -c /bin/hostname -f 2> /dev/null"',
    '"sh -c locale -a"',
    '"sh -c  -t -i"',
    '"sh -c openssl version"',
    '"bash -c id -Gn kafadmin"',
    '"sh -c /bin/sh -c ''date +%%s''"',
    '"sh -c /usr/share/lighttpd/create-mime.conf.pl"'
    ]

# This list allows for easy additions to the set of commands allowed
# to run shells in containers without having to without having to copy
# and override the entire run shell in container macro. Once
# https://github.com/falcosecurity/falco/issues/255 is fixed this will be a
# bit easier, as someone could append of any of the existing lists.
- list: user_known_shell_spawn_binaries
  items: []

# This macro allows for easy additions to the set of commands allowed
# to run shells in containers without having to override the entire
# rule. Its default value is an expression that always is false, which
# becomes true when the "not ..." in the rule is applied.
- macro: user_shell_container_exclusions
  condition: (never_true)

# Containers from IBM Cloud
- list: ibm_cloud_containers
  items:
    - icr.io/ext/sysdig/agent
    - registry.ng.bluemix.net/armada-master/metrics-server-amd64
    - registry.ng.bluemix.net/armada-master/olm

# In a local/user rules file, list the namespace or container images that are
# allowed to contact the K8s API Server from within a container. This
# might cover cases where the K8s infrastructure itself is running
# within a container.
- macro: k8s_containers
  condition: >
    (container.image.repository in (gcr.io/google_containers/hyperkube-amd64,
     gcr.io/google_containers/kube2sky,
     docker.io/sysdig/sysdig, sysdig/sysdig,
     fluent/fluentd-kubernetes-daemonset, prom/prometheus,
     falco_containers,
     falco_no_driver_containers,
     ibm_cloud_containers,
     velero/velero,
     quay.io/jetstack/cert-manager-cainjector, weaveworks/kured,
     quay.io/prometheus-operator/prometheus-operator,
     registry.k8s.io/ingress-nginx/kube-webhook-certgen, quay.io/spotahome/redis-operator,
     registry.opensource.zalan.do/acid/postgres-operator, registry.opensource.zalan.do/acid/postgres-operator-ui,
     rabbitmqoperator/cluster-operator, quay.io/kubecost1/kubecost-cost-model,
     docker.io/bitnami/prometheus, docker.io/bitnami/kube-state-metrics, mcr.microsoft.com/oss/azure/aad-pod-identity/nmi)
     or (k8s.ns.name = "kube-system"))

- macro: k8s_api_server
  condition: (fd.sip.name="kubernetes.default.svc.cluster.local")

- macro: user_known_contact_k8s_api_server_activities
  condition: (never_true)

- rule: Contact K8S API Server From Container
  desc: >
    Detect attempts to communicate with the K8S API Server from a container by non-profiled users. Kubernetes APIs play a 
    pivotal role in configuring the cluster management lifecycle. Detecting potential unauthorized access to the API server 
    is of utmost importance. Audit your complete infrastructure and pinpoint any potential machines from which the API server 
    might be accessible based on your network layout. If Falco can't operate on all these machines, consider analyzing the 
    Kubernetes audit logs (typically drained from control nodes, and Falco offers a k8saudit plugin) as an additional data 
    source for detections within the control plane.
  condition: >
    evt.type=connect and evt.dir=< 
    and (fd.typechar=4 or fd.typechar=6) 
    and container 
    and k8s_api_server 
    and not k8s_containers 
    and not user_known_contact_k8s_api_server_activities
  output: Unexpected connection to K8s API Server from container (connection=%fd.name lport=%fd.lport rport=%fd.rport fd_type=%fd.type fd_proto=%fd.l4proto evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: NOTICE
  tags: [maturity_stable, container, network, k8s, mitre_discovery, T1565]

- rule: Netcat Remote Code Execution in Container
  desc: > 
    Netcat Program runs inside container that allows remote code execution and may be utilized 
    as a part of a variety of reverse shell payload https://github.com/swisskyrepo/PayloadsAllTheThings/.
    These programs are of higher relevance as they are commonly installed on UNIX-like operating systems.
    Can fire in combination with the "Redirect STDOUT/STDIN to Network Connection in Container" 
    rule as it utilizes a different evt.type.
  condition: >
    spawned_process 
    and container 
    and ((proc.name = "nc" and (proc.cmdline contains " -e" or 
                                proc.cmdline contains " -c")) or
         (proc.name = "ncat" and (proc.args contains "--sh-exec" or 
                                  proc.args contains "--exec" or proc.args contains "-e " or
                                  proc.args contains "-c " or proc.args contains "--lua-exec"))
         )
  output: Netcat runs inside container that allows remote code execution (evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: WARNING
  tags: [maturity_stable, container, network, process, mitre_execution, T1059]

- list: grep_binaries
  items: [grep, egrep, fgrep]

- macro: grep_commands
  condition: (proc.name in (grep_binaries))

# a less restrictive search for things that might be passwords/ssh/user etc.
- macro: grep_more
  condition: (never_true)

- macro: private_key_or_password
  condition: >
    (proc.args icontains "BEGIN PRIVATE" or
     proc.args icontains "BEGIN OPENSSH PRIVATE" or
     proc.args icontains "BEGIN RSA PRIVATE" or
     proc.args icontains "BEGIN DSA PRIVATE" or
     proc.args icontains "BEGIN EC PRIVATE" or
     (grep_more and
      (proc.args icontains " pass " or
       proc.args icontains " ssh " or
       proc.args icontains " user "))
    )

- rule: Search Private Keys or Passwords
  desc: >
    Detect attempts to search for private keys or passwords using the grep or find command. This is often seen with 
    unsophisticated attackers, as there are many ways to access files using bash built-ins that could go unnoticed. 
    Regardless, this serves as a solid baseline detection that can be tailored to cover these gaps while maintaining 
    an acceptable noise level.
  condition: >
    spawned_process 
    and ((grep_commands and private_key_or_password) or
         (proc.name = "find" and (proc.args contains "id_rsa" or 
                                  proc.args contains "id_dsa" or 
                                  proc.args contains "id_ed25519" or 
                                  proc.args contains "id_ecdsa"
          )
        ))
  output: Grep private keys or passwords activities found (evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority:
    WARNING
  tags: [maturity_stable, host, container, process, filesystem, mitre_credential_access, T1552.001]

- list: log_directories
  items: [/var/log, /dev/log]

- list: log_files
  items: [syslog, auth.log, secure, kern.log, cron, user.log, dpkg.log, last.log, yum.log, access_log, mysql.log, mysqld.log]

- macro: access_log_files
  condition: (fd.directory in (log_directories) or fd.filename in (log_files))

# a placeholder for whitelist log files that could be cleared. Recommend the macro as (fd.name startswith "/var/log/app1*")
- macro: allowed_clear_log_files
  condition: (never_true)

- macro: trusted_logging_images
  condition: (container.image.repository endswith "splunk/fluentd-hec" or
              container.image.repository endswith "fluent/fluentd-kubernetes-daemonset" or
              container.image.repository endswith "openshift3/ose-logging-fluentd" or
              container.image.repository endswith "containernetworking/azure-npm")

- macro: containerd_activities
  condition: (proc.name=containerd and (fd.name startswith "/var/lib/containerd/io.containerd.snapshotter.v1.overlayfs/snapshots/" or
                                        fd.name startswith "/var/lib/rancher/k3s/agent/containerd/io.containerd.snapshotter.v1.overlayfs/snapshots" or
                                        fd.name startswith "/var/lib/containerd/tmpmounts/" or
                                        fd.name startswith "/var/lib/rancher/k3s/agent/containerd/tmpmounts/"))

- rule: Clear Log Activities
  desc: > 
    Detect clearing of critical access log files, typically done to erase evidence that could be attributed to an adversary's 
    actions. To effectively customize and operationalize this detection, check for potentially missing log file destinations 
    relevant to your environment, and adjust the profiled containers you wish not to be alerted on.
  condition: >
    open_write 
    and access_log_files 
    and evt.arg.flags contains "O_TRUNC" 
    and not containerd_activities
    and not trusted_logging_images 
    and not allowed_clear_log_files
  output: Log files were tampered (file=%fd.name evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority:
    WARNING
  tags: [maturity_stable, host, container, filesystem, mitre_defense_evasion, T1070, NIST_800-53_AU-10]

- list: data_remove_commands
  items: [shred, mkfs, mke2fs]

- macro: clear_data_procs
  condition: (proc.name in (data_remove_commands))

- macro: user_known_remove_data_activities
  condition: (never_true)

- rule: Remove Bulk Data from Disk
  desc: > 
    Detect a process running to clear bulk data from disk with the intention to destroy data, possibly interrupting availability 
    to systems. Profile your environment and use user_known_remove_data_activities to tune this rule.
  condition: > 
    spawned_process 
    and clear_data_procs 
    and not user_known_remove_data_activities
  output: Bulk data has been removed from disk (file=%fd.name evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority:
    WARNING
  tags: [maturity_stable, host, container, process, filesystem, mitre_impact, T1485]

- rule: Create Symlink Over Sensitive Files
  desc: > 
    Detect symlinks created over a curated list of sensitive files or subdirectories under /etc/ or 
    root directories. Can be customized as needed. Refer to further and equivalent guidance within the 
    rule "Read sensitive file untrusted".
  condition: >
    create_symlink 
    and (evt.arg.target in (sensitive_file_names) or evt.arg.target in (sensitive_directory_names))
  output: Symlinks created over sensitive files (target=%evt.arg.target linkpath=%evt.arg.linkpath evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: WARNING
  tags: [maturity_stable, host, container, filesystem, mitre_credential_access, T1555]

- rule: Create Hardlink Over Sensitive Files
  desc: > 
    Detect hardlink created over a curated list of sensitive files or subdirectories under /etc/ or 
    root directories. Can be customized as needed. Refer to further and equivalent guidance within the 
    rule "Read sensitive file untrusted".
  condition: >
    create_hardlink 
    and (evt.arg.oldpath in (sensitive_file_names))
  output: Hardlinks created over sensitive files (target=%evt.arg.oldpath linkpath=%evt.arg.newpath evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: WARNING
  tags: [maturity_stable, host, container, filesystem, mitre_credential_access, T1555]

- list: user_known_packet_socket_binaries
  items: []

- rule: Packet socket created in container
  desc: > 
    Detect new packet socket at the device driver (OSI Layer 2) level in a container. Packet socket could be used for ARP Spoofing 
    and privilege escalation (CVE-2020-14386) by an attacker. Noise can be reduced by using the user_known_packet_socket_binaries
    template list.
  condition: > 
    evt.type=socket and evt.dir=>
    and container 
    and evt.arg.domain contains AF_PACKET 
    and not proc.name in (user_known_packet_socket_binaries)
  output: Packet socket was created in a container (socket_info=%evt.args connection=%fd.name lport=%fd.lport rport=%fd.rport fd_type=%fd.type fd_proto=%fd.l4proto evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: NOTICE
  tags: [maturity_stable, container, network, mitre_credential_access, T1557.002]

- macro: user_known_stand_streams_redirect_activities
  condition: (never_true)

# As of engine version 20 this rule can be improved by using the fd.types[]
# field so it only triggers once when all three of std{out,err,in} are
# redirected.
#
# - list: ip_sockets
#   items: ["ipv4", "ipv6"]
#
# - rule: Redirect STDOUT/STDIN to Network Connection in Container once
#   condition: dup and container and evt.rawres in (0, 1, 2) and fd.type in (ip_sockets) and fd.types[0] in (ip_sockets) and fd.types[1] in (ip_sockets) and fd.types[2] in (ip_sockets) and not user_known_stand_streams_redirect_activities
#
# The following rule has not been changed by default as existing users could be
# relying on the rule triggering when any of std{out,err,in} are redirected.
- rule: Redirect STDOUT/STDIN to Network Connection in Container
  desc: >
    Detect redirection of stdout/stdin to a network connection within a container, achieved by utilizing a 
    variant of the dup syscall (potential reverse shell or remote code execution 
    https://github.com/swisskyrepo/PayloadsAllTheThings/). This detection is behavior-based and may generate 
    noise in the system, and can be adjusted using the user_known_stand_streams_redirect_activities template 
    macro. Tuning can be performed similarly to existing detections based on process lineage or container images, 
    and/or it can be limited to interactive tty (tty != 0).
  condition: > 
    dup 
    and container 
    and evt.rawres in (0, 1, 2) 
    and fd.type in ("ipv4", "ipv6") 
    and not user_known_stand_streams_redirect_activities
  output: Redirect stdout/stdin to network connection (gparent=%proc.aname[2] ggparent=%proc.aname[3] gggparent=%proc.aname[4] fd.sip=%fd.sip connection=%fd.name lport=%fd.lport rport=%fd.rport fd_type=%fd.type fd_proto=%fd.l4proto evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: NOTICE
  tags: [maturity_stable, container, network, process, mitre_execution, T1059]

- list: allowed_container_images_loading_kernel_module
  items: []

- rule: Linux Kernel Module Injection Detected
  desc: >
    Inject Linux Kernel Modules from containers using insmod or modprobe with init_module and finit_module
    syscalls, given the precondition of sys_module effective capabilities. Profile the environment and consider
    allowed_container_images_loading_kernel_module to reduce noise and account for legitimate cases.
  condition: > 
    kernel_module_load 
    and container 
    and thread.cap_effective icontains sys_module 
    and not container.image.repository in (allowed_container_images_loading_kernel_module)
  output: Linux Kernel Module injection from container (parent_exepath=%proc.pexepath gparent=%proc.aname[2] gexepath=%proc.aexepath[2] module=%proc.args res=%evt.res evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info) 
  priority: WARNING
  tags: [maturity_stable, host, container, process, mitre_persistence, TA0003]

- rule: Debugfs Launched in Privileged Container
  desc: > 
    Detect file system debugger debugfs launched inside a privileged container which might lead to container escape. 
    This rule has a more narrow scope.
  condition: >
    spawned_process 
    and container
    and container.privileged=true
    and proc.name=debugfs
  output: Debugfs launched started in a privileged container (evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: WARNING
  tags: [maturity_stable, container, cis, process, mitre_privilege_escalation, T1611]

- rule: Detect release_agent File Container Escapes
  desc: > 
    Detect an attempt to exploit a container escape using release_agent file. 
    By running a container with certains capabilities, a privileged user can modify 
    release_agent file and escape from the container.
  condition: >
    open_write 
    and container 
    and fd.name endswith release_agent 
    and (user.uid=0 or thread.cap_effective contains CAP_DAC_OVERRIDE) 
    and thread.cap_effective contains CAP_SYS_ADMIN
  output: Detect an attempt to exploit a container escape using release_agent file (file=%fd.name cap_effective=%thread.cap_effective evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: CRITICAL
  tags: [maturity_stable, container, process, mitre_privilege_escalation, T1611]

- list: docker_binaries
  items: [docker, dockerd, containerd-shim, "runc:[1:CHILD]", pause, exe, docker-compose, docker-entrypoi, docker-runc-cur, docker-current, dockerd-current]

- list: known_ptrace_binaries
  items: []

- macro: known_ptrace_procs
  condition: (proc.name in (known_ptrace_binaries))

- macro: ptrace_attach_or_injection
  condition: >
    (evt.type=ptrace and evt.dir=> and
    (evt.arg.request contains PTRACE_POKETEXT or
    evt.arg.request contains PTRACE_POKEDATA or
    evt.arg.request contains PTRACE_ATTACH or
    evt.arg.request contains PTRACE_SEIZE or
    evt.arg.request contains PTRACE_SETREGS))

- rule: PTRACE attached to process
  desc: > 
    Detect an attempt to inject potentially malicious code into a process using PTRACE in order to evade 
    process-based defenses or elevate privileges. Common anti-patterns are debuggers. Additionally, profiling 
    your environment via the known_ptrace_procs template macro can reduce noise. 
    A successful ptrace syscall generates multiple logs at once.
  condition: > 
    ptrace_attach_or_injection 
    and proc_name_exists 
    and not known_ptrace_procs
  output: Detected ptrace PTRACE_ATTACH attempt (proc_pcmdline=%proc.pcmdline evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: WARNING
  tags: [maturity_stable, host, container, process, mitre_privilege_escalation, T1055.008]
  
- rule: PTRACE anti-debug attempt
  desc: > 
    Detect usage of the PTRACE system call with the PTRACE_TRACEME argument, indicating a program actively attempting 
    to avoid debuggers attaching to the process. This behavior is typically indicative of malware activity.
    Read more about PTRACE in the "PTRACE attached to process" rule.
  condition: > 
    evt.type=ptrace and evt.dir=> 
    and evt.arg.request contains PTRACE_TRACEME 
    and proc_name_exists
  output: Detected potential PTRACE_TRACEME anti-debug attempt (proc_pcmdline=%proc.pcmdline evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: NOTICE
  tags: [maturity_stable, host, container, process, mitre_defense_evasion, T1622]

- macro: private_aws_credentials
  condition: >
    (proc.args icontains "aws_access_key_id" or
    proc.args icontains "aws_secret_access_key" or
    proc.args icontains "aws_session_token" or
    proc.args icontains "accesskeyid" or
    proc.args icontains "secretaccesskey")

- rule: Find AWS Credentials
  desc: >
    Detect attempts to search for private keys or passwords using the grep or find command, particularly targeting standard 
    AWS credential locations. This is often seen with unsophisticated attackers, as there are many ways to access files 
    using bash built-ins that could go unnoticed. Regardless, this serves as a solid baseline detection that can be tailored 
    to cover these gaps while maintaining an acceptable noise level. This rule complements the rule "Search Private Keys or Passwords".
  condition: >
    spawned_process 
    and ((grep_commands and private_aws_credentials) or
         (proc.name = "find" and proc.args endswith ".aws/credentials"))
  output: Detected AWS credentials search activity (proc_pcmdline=%proc.pcmdline proc_cwd=%proc.cwd group_gid=%group.gid group_name=%group.name user_loginname=%user.loginname evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: WARNING
  tags: [maturity_stable, host, container, process, aws, mitre_credential_access, T1552]

- rule: Execution from /dev/shm
  desc: > 
    This rule detects file execution in the /dev/shm directory, a tactic often used by threat actors to store their readable, writable, and 
    occasionally executable files. /dev/shm acts as a link to the host or other containers, creating vulnerabilities for their compromise 
    as well. Notably, /dev/shm remains unchanged even after a container restart. Consider this rule alongside the newer 
    "Drop and execute new binary in container" rule.
  condition: >
    spawned_process 
    and (proc.exe startswith "/dev/shm/" or 
        (proc.cwd startswith "/dev/shm/" and proc.exe startswith "./" ) or 
        (shell_procs and proc.args startswith "-c /dev/shm") or 
        (shell_procs and proc.args startswith "-i /dev/shm") or 
        (shell_procs and proc.args startswith "/dev/shm") or 
        (proc.cwd startswith "/dev/shm/" and proc.args startswith "./" )) 
    and not container.image.repository in (falco_privileged_images, trusted_images)
  output: File execution detected from /dev/shm (evt_res=%evt.res file=%fd.name proc_cwd=%proc.cwd proc_pcmdline=%proc.pcmdline user_loginname=%user.loginname group_gid=%group.gid group_name=%group.name evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: WARNING
  tags: [maturity_stable, host, container, mitre_execution, T1059.004]

# List of allowed container images that are known to execute binaries not part of their base image.
- list: known_drop_and_execute_containers
  items: []

- macro: known_drop_and_execute_activities
  condition: (never_true)

- rule: Drop and execute new binary in container
  desc: >
    Detect if an executable not belonging to the base image of a container is being executed.
    The drop and execute pattern can be observed very often after an attacker gained an initial foothold.
    is_exe_upper_layer filter field only applies for container runtimes that use overlayfs as union mount filesystem.
    Adopters can utilize the provided template list known_drop_and_execute_containers containing allowed container 
    images known to execute binaries not included in their base image. Alternatively, you could exclude non-production
    namespaces in Kubernetes settings by adjusting the rule further. This helps reduce noise by applying application 
    and environment-specific knowledge to this rule. Common anti-patterns include administrators or SREs performing 
    ad-hoc debugging.
  condition: >
    spawned_process
    and container
    and proc.is_exe_upper_layer=true 
    and not container.image.repository in (known_drop_and_execute_containers)
    and not known_drop_and_execute_activities
  output: Executing binary not part of base image (proc_exe=%proc.exe proc_sname=%proc.sname gparent=%proc.aname[2] proc_exe_ino_ctime=%proc.exe_ino.ctime proc_exe_ino_mtime=%proc.exe_ino.mtime proc_exe_ino_ctime_duration_proc_start=%proc.exe_ino.ctime_duration_proc_start proc_cwd=%proc.cwd container_start_ts=%container.start_ts evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: CRITICAL
  tags: [maturity_stable, container, process, mitre_persistence, TA0003, PCI_DSS_11.5.1]

# RFC1918 addresses were assigned for private network usage
- list: rfc_1918_addresses
  items: ['"10.0.0.0/8"', '"172.16.0.0/12"', '"192.168.0.0/16"']

- macro: outbound
  condition: >
    (((evt.type = connect and evt.dir=<) or
      (evt.type in (sendto,sendmsg) and evt.dir=< and
       fd.l4proto != tcp and fd.connected=false and fd.name_changed=true)) and
     (fd.typechar = 4 or fd.typechar = 6) and
     (fd.ip != "0.0.0.0" and fd.net != "127.0.0.0/8" and not fd.snet in (rfc_1918_addresses)) and
     (evt.rawres >= 0 or evt.res = EINPROGRESS))

- list: ssh_non_standard_ports
  items: [80, 8080, 88, 443, 8443, 53, 4444]

- macro: ssh_non_standard_ports_network
  condition: (fd.sport in (ssh_non_standard_ports))

- rule: Disallowed SSH Connection Non Standard Port
  desc: > 
    Detect any new outbound SSH connection from the host or container using a non-standard port. This rule holds the potential 
    to detect a family of reverse shells that cause the victim machine to connect back out over SSH, with STDIN piped from 
    the SSH connection to a shell's STDIN, and STDOUT of the shell piped back over SSH. Such an attack can be launched against 
    any app that is vulnerable to command injection. The upstream rule only covers a limited selection of non-standard ports. 
    We suggest adding more ports, potentially incorporating ranges based on your environment's knowledge and custom SSH port 
    configurations. This rule can complement the "Redirect STDOUT/STDIN to Network Connection in Container" or 
    "Disallowed SSH Connection" rule.
  condition: > 
    outbound 
    and proc.exe endswith ssh 
    and fd.l4proto=tcp 
    and ssh_non_standard_ports_network
  output: Disallowed SSH Connection (connection=%fd.name lport=%fd.lport rport=%fd.rport fd_type=%fd.type fd_proto=%fd.l4proto evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty %container.info)
  priority: NOTICE
  tags: [maturity_stable, host, container, network, process, mitre_execution, T1059]

- list: known_memfd_execution_binaries
  items: [runc]

- macro: known_memfd_execution_processes
  condition: > 
    (proc.name in (known_memfd_execution_binaries))
    or (proc.pname in (known_memfd_execution_binaries))
    or (proc.exepath = "memfd:runc_cloned:/proc/self/exe")
    or (proc.exe = "memfd:runc_cloned:/proc/self/exe")


- rule: Fileless execution via memfd_create
  desc: >
    Detect if a binary is executed from memory using the memfd_create technique. This is a well-known defense evasion 
    technique for executing malware on a victim machine without storing the payload on disk and to avoid leaving traces 
    about what has been executed. Adopters can whitelist processes that may use fileless execution for benign purposes 
    by adding items to the list known_memfd_execution_processes.
  condition: >
    spawned_process
    and proc.is_exe_from_memfd=true
    and not known_memfd_execution_processes
  output: Fileless execution via memfd_create (container_start_ts=%container.start_ts proc_cwd=%proc.cwd evt_res=%evt.res proc_sname=%proc.sname gparent=%proc.aname[2] evt_type=%evt.type user=%user.name user_uid=%user.uid user_loginuid=%user.loginuid process=%proc.name proc_exepath=%proc.exepath parent=%proc.pname command=%proc.cmdline terminal=%proc.tty exe_flags=%evt.arg.flags %container.info)
  priority: CRITICAL
  tags: [maturity_stable, host, container, process, mitre_defense_evasion, T1620]