An integrated threat protection solution designed to detect, investigate, and respond to cyber threats across Microsoft 365 services.
That message can be a real malware warning or a fake virus alert designed to keep the screen occupied and pressure action.
- If the warning is inside Microsoft Edge or another browser, close it with Ctrl + Shift + Esc to open Task Manager, select the browser, and choose End task.
- Then open Start > Settings > Update & Security > Windows Security > Virus & threat protection.
- Under Current threats, select Scan options.
- Run a Full scan first.
- If threats keep returning or the PC still behaves as infected after restart, run Windows Defender Offline scan from the same Scan options page. Warning: the PC will restart before the scan starts, so save any open work first.
- If Microsoft reports a threat is only partially removed, run the Malicious Software Removal Tool:
- Press Windows key + R
- Type %windir%\system32\mrt.exe
- Select OK
- If prompted, select Yes
- Follow the prompts to scan and clean the PC
- After that, restart the PC and install the latest updates.
If the browser showed a pop-up claiming the computer is infected, also remove any suspicious browser notification permissions and clear cached files. In Edge, go to Settings > Cookies and site permissions > Notifications and remove unfamiliar entries.
If malware has already caused lasting damage, a PC reset or reinstall may be required. Warning: this can require restoring files from backup, and backups created during infection may also be affected.