My mother's Windows computer started showing fake antivirus warnings after she downloaded something. The alert changes each time the computer starts and sometimes blocks access to other applications. Windows' built-in malware scan did not appear to fix the problem, although another full scan is currently running. What steps should I take to determine whether this is malware or just malicious browser notifications, and safely get the computer working again?
4 Answers
Deleting cookies and temporary files alone usually will not remove installed malware, but it can help clear browser-based junk. Focus first on removing suspicious browser notification permissions, extensions, and recently installed applications, then run an offline or full security scan.
This may not be a traditional virus. Rogue website notifications can look exactly like antivirus warnings and keep appearing on the desktop. Check the browser’s notification permissions and remove any unfamiliar websites, then clear the browser’s data and uninstall anything suspicious that was recently added.
If the pop-ups continue after checking the browser, back up important personal files and use Windows’ reset option that keeps personal files while removing programs and settings. Make sure the backup is safe first, since malware could potentially be included in files you copy.
For a system you believe is genuinely compromised, the most thorough fix is a clean Windows installation. Back up only essential personal files, disconnect or remove other internal drives, create a Windows installation USB from a trusted computer, delete the partitions on the Windows drive during setup, and reinstall from scratch. Afterward, fully update Windows and Defender, scan the backup, and restore files carefully.
I’m planning to try that if the scans and browser cleanup don’t solve it. A reset may be the safest option.