A Microsoft Defender alert no longer appearing is a good sign, but it does not confirm by itself that the malware is fully gone.
Use this check path:
- Open Windows Security by searching for it from Start.
- Select Virus & threat protection.
- Make sure Microsoft Defender Antivirus is active and not replaced by another antivirus product. If a non-Microsoft antivirus is installed, Defender can be in passive mode or disabled.
- Under Virus & threat protection settings, select Manage settings and make sure these are On:
- Cloud-delivered protection
- Automatic sample submission
- Under Virus & threat protection updates, select Check for updates, then under Threat definitions select Check for updates.
- Run a scan from Virus & threat protection.
- If the threat was previously reported as only partly removed, run the Malicious Software Removal Tool:
- Press Windows key + R
- Run %windir%\system32\mrt.exe
- Follow the prompts to scan and clean the PC
- If the same malware comes back, run Windows Defender Offline scan:
- Start > Settings > Update & Security > Windows Security > Virus & threat protection
- Under Current threats, select Scan options
- Select Windows Defender Offline scan > Scan now
Important:
- Running more than one antivirus or antispyware program at the same time can reduce performance and make the PC unstable.
- If another antivirus was installed for cleanup, uninstall it after use unless it is intended to be the main antivirus.
- Before removing another security product, make sure Microsoft Defender Antivirus is enabled.
If suspicious files are still present but not detected, submit the files to Microsoft for analysis.
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