What is hack32 and hack64?

I bought a used notebook and got the message this morning: Virus found System is being scanned I checked and the virus was: Hack 32 and hack 64 what is it and what does it do? Should I be worried? Windows 10 pro LG happy holidays ^^

Yes, you should be concerned and reinstall Windows completely. An AV program usually makes much more precise statements about a malware find, but you have not communicated this here and I will not pull any information out of anyone's nose on Christmas Day.

I thought windows has an antivirus program? At least that's what the seller said to me: / well, otherwise it just says that it can probably instabilize the system, what exactly does this thing do?

Windows 10 certainly has the Defender. But no anti-virus program is even as reliable as all laypeople believe. Brainwashing works.

Nobody can tell you what this thing does, because nobody can only recognize something from a name like Hack32 / 64.

This can be anything from harmless cheat programs for games to keygens for software to Trojan horses.

Now have a closer look and it says: hack32: KeyGen and hack64 says nothing what does a "KeyGen" do?

And then there's another hack kak: HackTool.Win32.HackAV

A key generator generates registration or serial numbers for full versions of expensive programs. So as such is illegal to use something like that. Since these things also come from dubious sources and are also often contaminated with malware, your PC is now co-compromised and no longer trustworthy.