I'm russian.
I have VAC in CSGO because I got hacked. Explanation below. Go to hell if you don't believe me.

Why I'm VAC banned:

Mail.ru service is terrible. On June 18, 2018, a window appeared that said that my steam password was changed, but the old password didn't work. I immediately got scared and tried to restore it, the password to my mail wasn't changed and I saw mails in the deleted messages about changing the steam password.
I was hacked, but I didn't have a steam mobile authenticator, which explains everything. You see, without it, all a hacker needs to do is change the password to his own using access to mail, and then it's just a matter of imagination.
By the way, how did my mail got hacked at all? As I said, the Mail.ru service is terrible and its main problem is its potato level protection. My data, like millions of others, was simply leaked in a massive hack. And I didn't have a mobile authenticator in my mail either.
But back to June, on the 19th, with the help of Steam support and a whole night of nightmares, I was able to restore my account. After that I logged in and saw a yellow window saying that I got VAC banned.
The result of 10 minutes of fun for a hacker with cheats made a terrible red sign on my profile, a total loss of trust in me because of it, depression and anxiety that I still have. For some, VAC ban is just a joke, but not for me.
In conclusion, always take care of the security of your account.