Trojan.Gen backdoor may prevent access to USB Flash Drive
I was working in my favorite finance program on my Vista machine last night, and when it went to back up to the flash drive an error came up “Back up drive “F” is not accessible.” At first I thought I might have removed it when doing some hardware update, but upon checking it was firmly plugged in. I removed it, heard the “Bong” sound, plugged it back in, another “Bong” but no access. I went into explorer and it was there, but when I clicked on it, the message that popped up read “Please insert a disk into removable disk drive “F.” I have never seen this message before and was shocked since it worked 7 days ago. I had not added any programs or updated any applications for awhile, so had no idea what was causing this. I started researching this error message on Google, and noticed it was not acting normal. Usually when I type something in Google, it brings up lots of matches and sites related to the query. It now brought up advertising sites only on the first page, and I had to go to the second page to get any normal results. I found lots of hits but went with the easy ones first.
I plugged the flash drive into my Win 7 machine and found it worked perfect. No virus using Avast. I plugged it into my XP machine running AVG, and again it worked perfect. I returned to my Vista machine and it was there but not accessible. I went into disk management from control panel, and checked it out there. It showed up but had readings of “0” bytes, “No media detected”, and “0” storage available. I could change the drive letter on it, but that made no difference. I decided to back up the data onto another machine and then tried to format it on the Vista machine. It could not access it to format giving me an error of “No media.” Back to Google with some new keywords, only this time I got an error that the “TCP-IP pass through filter has stopped working.” Once that message came up, no more internet. Now I had a new failure to contend with. Maybe the net card was flaking out? Maybe the hard drive or mother board? Not sure where to start, I went into the registry to find out where the “TCP-IP pass through filter” was. I found it in lots of places and referring to an “msippsth.dll” file. I found the file in the “windows\system32” folder, but it did not scan as a virus or anything bad with AVG or Avast. I went back to Google on a working machine and typed in this new information.
I finally found the answer on a site www.threatexpert.com by typing in the file I found, “msippsth.dll.” It came up with a “Trojan.Gen, backdoor” dated 7/28/2010. It detailed all the keys made and other files that might be installed. Back to the Vista machine and using a different program that will allow deletion of protected keys, in case they were secured, I proceeded to remove all traces of this infection. I then restarted and still had no Internet. Back to Google on a good machine and after spending hours with all the different combinations of keywords I had, finally found I needed to run the command “netsh winsock reset” from a command prompt with admin rights. That fixed it and now when I plugged in my flash drive, it could be seen and accessed, and Google started working properly, no more advertising on the first screen of information.
Not sure what this was, how long it has been on my machine, how it got installed or got past Vista’s UAC, firewall, virus and malware protection, what information it was intercepting, but it did and never showed any problems until I tried to use the flash drive. Not sure what caused the “TCP-IP pass through filter” to stop either but I am glad it did or I might not have been able to figure this out in the few days that it took.
- Jeff
(2010-11-08)