Question Windows Defender Turns up nothing, but do I have a virus?

[JCMiller23]

Symptoms:

(all of these happen only when leaving my computer on overnight, all of them happen after I've purchased a game that I think was a bootleg copy or pirated - installation app gave it away)

1. I regularly get various errors on my VPN when leaving it on
   1. NordVPN asks me to enable background processes on it sometimes when I start up my computer, sometimes doesn't
2. Notification settings changed on my outlook/mail program without me doing anything (after leaving on overnight)
3. Computer stops working properly sometimes after leaving it on, can't run any program or shut down from the UI. Ctrl-Alt-Del doesn't work
4. 2nd monitor (TV via HDMI) randomly stops working after leaving computer on overnight and won't work again.

Do I have a virus or some kind of backdoor to my system opened up? What can I do if windows defender doesn't detect it?

 

[Lutfij]

Welcome to the forums, newcomer!

You could use Malwarebytes and see if your results come through negative.

(all of these happen only when leaving my computer on overnight, all of them happen after I've purchased a game that I think was a bootleg copy or pirated - installation app gave it away)
You might want to avoid using counterfeit app's/games. You should also practice a healthy browsing habit by not visiting suspicious sites and or download things that you didn't click on.

 

[BFG-9000]

No antivirus reverts all changes by all viruses in their repairs. Some of these changes don't appear suspicious as they aren't themselves malicious--but can make it easier to later download actual malware later. In the olden days programs like Spybot and AdAware claimed to "inoculate" system settings and files by copying them and so were able to revert any changes afterwards.

The only way to be reasonably sure is to blow the partition and reinstall. The really paranoid will also reflash the BIOS and toss any storage devices, as those can have some really difficult to check service tracks of virtually unlimited size to hide malware in.

 

[JCMiller23]

Welcome to the forums, newcomer!

You could use Malwarebytes and see if your results come through negative.

(all of these happen only when leaving my computer on overnight, all of them happen after I've purchased a game that I think was a bootleg copy or pirated - installation app gave it away)
You might want to avoid using counterfeit app's/games. You should also practice a healthy browsing habit by not visiting suspicious sites and or download things that you didn't click on.

This worked like a charm! Turned up some bitcoin miners in my "HKLM" folder and some other stuff I don't understand, thank you!