Environment

• System : Windows10
• Set System variable: http_proxy=http://a.b.c.d:10811

Phenomenon

After setting, explorer will connect 50051, 50052, 50053 port iteratively per three seconds.

thought

Af first, think it as the problem of Windows.
Then search get https://answers.microsoft.com/zh-hans/windows/forum/all/explorer%E4%B8%80%E7%9B%B4%E5%9C%A8%E8%AE%BF/7395ec69-6357-45e6-b794-72cad3b71de6

Then find it is wechat driver cause explorer to establish connection.
https://developers.weixin.qq.com/community/enterprisewechat/doc/000cacfa3a4c0086845af0caf56c01

After remove the wechat driver and restart explorer. The above ports explorer stop visit.

Here are the packages of removed wechat driver.
WXDrive.zip

How to replicate

1. set global system variable : http_proxy=http://a.b.c.d:10811
2. extract package to C:\Program Files (x86)\WXDrive
3. restart windows explorer
4. Visit connectting log on a.b.c.d server.( Please block .localhost. before: "regexp:.*localhost.*")