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Published Apr 12, 2012 | Updated Sep 15, 2017

Win32/Sirefef

Severe |Detected with Windows Defender Antivirus

Aliases: ZeroAccess (other) Zero Access (other)

Summary

Microsoft security software detects and removes this threat.

This family of malware uses stealth to hide its presence on your PC. Trojans in this family can do different things, including:

  • Downloading and running other files
  • Contacting remote hosts
  • Disabling security features

Members of the family can also change search results, which can generate money for the hackers who use Sirefef.

Variants of Win32/Sirefef might be installed by other malware, including variants of the Trojan:Win32/Necurs family.

Find out ways that malware can get on your PC.

Use the following free Microsoft software to detect and remove this threat:

You should also run a full scan. A full scan might find other, hidden malware.

Note that as part of the cleaning, our software might change some Windows services back to their default settings. If you had previously changed these settings, you might need to change them again.

The services that are reset include:

  • BFE – Base Filtering Engine
  • Iphlsvc – IP helper Service
  • MSMpSvc – Microsoft Antimalware service – MSE/FEP/SCEP
  • Sharedaccess – Internet Connection Sharing
  • WinDefend – Microsoft Antimalware service
  • Wscsvc - Windows Security Center
Get more help

You can also visit our advanced troubleshooting page or search the Microsoft virus and malware community for more help.

If you’re using Windows XP, see our Windows XP end of support page.

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