VAC

Alright, so this past week i've been cheating in comp. on one of my smurf accounts. 2-3 days later, i come on to play a game of cs, hopped on my 2nd comp. match of the day, and 20 rounds in, i'm vacced? I've been using a private cheat, that is still undetected and i have been using it on my other accounts. For some reason, this is the only account that got VAC using the same cheat on the other accounts.
What happened here?
My possible solutions:
1. Turned FOV to 20 then immediately turned it back down to 1.
2. I was bhopping most of the time, but they were legit hops, no external source helping me.
3. idk, i was going legit.
Anyone have any ideas? Thanks.