Cleaning up after WMF exploit – BHO removal
Browser helper objects (BHO’s) are listed in the registry and load with explorer when it runs (Internet Explorer/ File explorer are so closely tied it affects both.) I’ve used BHOdemon in the past to identify and disable BHO’s and a tool like that is the preferred method. However, in my case, this is a disposable virtual machine and I used the “blunt object” approach…. regedit.
I had identified one file in the infestation as a BHO by viewing it with a text editor and finding a text string identifying that it was a BHO. 3.00.13.dll was the file name. In the registry, I went to the following key HKLM\Software\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects and deleted every entry. This is not the recommended way of dealing with it, but I was already several hours into cleaning up my virtual machine and didn’t have any “good” BHO’s that I was concerned that would disable.
Even if there were “good” BHO’s that I had disabled I would image a reinstall of the BHO would fix it. (Some good one’s for example might be an Acrobat reader BHO)… Anyway, I had forgot to detail that step in the earlier writeups and wanted to make sure there was a complete accounting.