Detected?

So basically. I have bought a smurf and i want to hack on it. If a hack gets detected like 2 days after i used it and i dont use it at the moment it gets detected will i still get a vac?\

Sorry for not putting help request in the title )

Yes, of course you will get a ban.

But how do so many people still not get banned if they use a hack for 1 game? Just a public hack.