Windows Firewall – How to Restore Windows Firewall After Malware Deletion

malwarewindows 7windows firewall

Yesterday I visited some web site, and apparently got infected via some Flash exploit. Microsoft Security essentials immediately kicked in, and displayed a warning about four items:

> Trojan:Win64/Sirefef.B 
> DDoS:Win32/Fareit.gen!A 
> Rogue:Win32/FakeRean
> PWS:Win32/Karagany.A

I deleted them, and thought Security Essentials caught the infection before it did any harm. However, today I discovered that Windows Firewall service disappeared completely, I cannot visit Firewall in the Control Panel, "Base Filtering Engine" service is marked as disabled. Looked in the Process Explorer, didn't see anything suspicious. Additional antivirus scans didn't turn up anything.

Questions:

  • How can I return my firewall back to its life?
  • What else these viruses break, so I can check if I'm affected?

I know the best course of action is to re-install Windows or restore from backup. I would like to know if there is any other option…

Best Answer

You should probably run Malware Bytes or SpyBot S&D to make sure there isn't anything else (malware/spyware/adware) messing with your system. A free online scan at eSet just to make sure its all gone might be a good idea.

Once you know the system is clean, open an elevated command prompt and run SFC /SCANNOW to run the System File Check. When it is done, reboot and see if your firewall service is back.

If SFC doesn't work you can try this diagnostic from Microsoft.

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