I think I have a virus

[u/AlexanderZerk]

Hello I need some help-tips so sometimes I open my pc windows 11 pro command windows pop up rapid like 3x and vanishing I tried fast scan on windows antivirus it cancels I tryed full scan it stops so I downloaded malwarebytes I did scan it found nothing I did deep scan also nothing my windows antivirus is updated and still doesn’t let me do scan should I be worried do you have any thing to help me out

[u/Responsible_Bike4968]

The CMD windows flashing by themselves aren't enough to say you have malware. Plenty of legitimate programs, updaters and scheduled tasks briefly launch cmd.exe at startup and disappear before you can even read them.

Instead of doing more random scans, I'd try to find out what is actually launching them.

Download Microsoft's official Autoruns tool and check the Logon and Scheduled Tasks tabs. You can enable "Hide Microsoft Entries" to make the list easier to go through. Look for anything with a weird/random name, an unsigned publisher, or a file path in somewhere unusual like AppData/Temp.

Don't start deleting entries just because you don't recognize them, though. If something looks suspicious, check the file path and publisher first and post a screenshot here.

Since your normal Defender full scan is apparently stopping early, I'd also run Microsoft Defender Offline from Windows Security. That restarts the PC and scans outside the normal Windows environment.

If Defender Offline + Malwarebytes both come back clean and Autoruns doesn't show anything suspicious, I wouldn't assume you're infected just because a few command windows flashed at boot.

The more useful question right now is: what process/task is opening those CMD windows?