Hello Igado and welcome to Seven Forums. A few questions to try and help you better.
1. Are you trying to install Windows Updates or some other updates?
2. Which anti-virus are you using?
3. When your anti-virus detects the malware, open Task Manager. Do you see something called msa.exe and/or b.exe?
It's possible that your computer was previously infected with malware before you tried to install the updates. No anti-malware program is 100% effective 100% of the time. (If there was such a thing we'd all be using it.) If you can system restore again (to before the updates) I'd recommend full scans with these additional free programs. They each have good reputations of finding things other programs miss: Malwarebytes ESET Online Scanner Windows Defender Offline
(This is a bootable malware remover. You will need to create the CD/DVD/USB Flash on a computer that is NOT
Follow the instructions exactly for each scan.