Here's the reason or u can search on steam support site too
help.steampowered.com
i said , i got vac cuz of Spin script
but i was wrong after i contacted steam support
they said that if Unknown Source of application try to open when games running with steam then maybe it causes vac
Because VAC [Valve anto cheat] scan each time your tasking process
i tried to install IMD cracked version and when i open keygen.exe it was happened as got vac
there is a solution for not to get vac
Always turn on Firewall services
Windows defender services and give all drive permission [ windows defender is the best anto virus software , this will scan for unknown application]
Do Not try to chance steam services Drivers like GPU
Dont use idle programs
if anyone have more experience about this then he/she can add more solution and causes here
Happy Hunting

Steam Support :: I've been VAC banned
i said , i got vac cuz of Spin script
but i was wrong after i contacted steam support
they said that if Unknown Source of application try to open when games running with steam then maybe it causes vac
Because VAC [Valve anto cheat] scan each time your tasking process
i tried to install IMD cracked version and when i open keygen.exe it was happened as got vac
there is a solution for not to get vac
Always turn on Firewall services
Windows defender services and give all drive permission [ windows defender is the best anto virus software , this will scan for unknown application]
Do Not try to chance steam services Drivers like GPU
Dont use idle programs
if anyone have more experience about this then he/she can add more solution and causes here
Happy Hunting