Explorer.exe affected with Win32:Dropper-gen [Drp] virus, nothing worked so far

ldc

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Nov 10, 2010
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I first tried the method from here:
Malware Tips

Then on a regular restart and on clicking the 'Windows Explorer' shortcut from my taskbar Avast pops up again telling me 'Avast shield has blocked a threat, no further action is required'.

So, I followed the steps in the sticky in this section:
Simple and Free guide to removing Malware

On a 'Safe Mode' restart and fullscan of Malware Bytes it shows no threats. Then running combofix it finds a few problems and deletes them. Then I run CCleaner and clean the Registry. On a normal restart and click of 'Windows Explorer' Avast pops up again with the above mentioned warning.

What do I do?
 

ldc

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Nov 10, 2010
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Alright. Problem solved. For those interested here goes:

As my question says, I tried multiple scans with Malware Bytes and couldn't find anymore affected files (after the initial scan deleted a lot of infection) but Avast kept popping up with warning for Explorer with the 'dropper-gen' virus. I tried a rollback with system restore from a bootable USB of Windows 7 and the problem popped up again after a while.

FINALLY, it struck me to simply use sfc /scannow in normal Windows mode (not even 'safe mode'.) It replaced the Explorer.exe file along with some other system files, most probably. Then it restarted again in normal mode for completion of the task. This made my customised themes all disappear, which I am fine with.

Without doing anything more I restarted in safe mode and ran Malware Byes and ComboFix for good measure. Neither found any infection. Then scheduled a boot-time scan with Avast and it found no errors either.

It's been more than 12 hours now and clicking on the Windows Explorer icon doesn't bring up any pop-ups from Avast. So, I guess problem solved! :D