VAC Bans
We don’t have any control over the VAC system. Some devs can issue a similar ban, but those are called Game Bans and will not have the VAC tag in the ban description in your profile. Instead, it will simply say “Game ban on record” (see image). We currently do not issue out these game bans.
We also do not have the ability to see what triggered a VAC ban and have no ability to sway Valve on the matter. Clicking “info” only shows the normal VAC information page:
https://help.steampowered.com/en/faqs/view/571A-97DA-70E9-FF74
Generally, cheat/cracking software that injects into a game or otherwise modifies a game that is VAC secured may trigger VAC. An example of cheating software is something that injects into a game’s DLLs. In some cases, you may get VAC banned if someone you had shared your Steam library with uses your library to cheat (i.e. using Steam Family Sharing).
Your only recourse is to contact Valve if you feel the ban was in error.