The first time I logged into WeChat, I found someone passing the verification code by SMS after sending the verification code.

Unknown. According to the information of querying WeChat login, querying WeChat login is unknown. When downloading WeChat, someone logs in to your WeChat through the verification code. If it wasn't for me, the content of the message would be leaked. Please check whether the mobile phone is implanted with Trojan horse and whether the short message is forwarded. This situation is because your SMS verification code was leaked to others for some reason, which led to your WeChat being logged in by others. Or the mobile phone number you used has been used by others before, and the other party has not cancelled the WeChat account.