Cheat Engine

[cooladam]

I use cheat engine frequently for single player games on my emulators, and have never used it for anything online. I recently tried booting up dead by daylight after closing cheat engine and was told to close cheat engine before starting. I didn't have cheat engine open and couldn't find anything in task manager. It let me play after restarting my PC but my main concern is that I played TF2 in that time before I got the notification that I needed to "close" cheat engine.
Will VAC detect cheat engine even when it's not open? It's been a few days now and nothing has happened to my account but the fear of losing everything after a decade+ of playing is still worrying.

[atom0s]

Being told to close Cheat Engine when it's not running is generally a sign that you had used CE recently with its driver feature(s). It means the driver was still loaded and could be easily detected/seen by other games or anti-cheats.

VAC generally won't do anything regarding a ban unless you intentionally try and manipulate the specific process that loaded it. Just having the CE driver running/enabled is unlikely to trigger any ban/issue. However, VAC is the kind of AC that can be updated and changed at any given time without notice, so there is a possibility that Valve may eventually scan for and ban just having the driver loaded. (However, this is very unlikely.)