Yes, it's most likely UD. The safest way to use public hacks (still much riskier than paid or self-made cheats) is to only use them within 48 hours of release. Most people I know use them up to 72 hours after release, I personally go for 24 hours, 36 at most, just to make sure it's UD. But still, you'll always have that chance of getting VAC'd, so if you don't want to get banned just don't cheat