Help, Avast Scanner disables

[lil]

Hi!
 
I've spent a week without internet connexion and now life goes back to normal cause I'm connected again. The problem is that I used a pen which had a Trojan on it during this "disconnected" week. I couldn't move it to the chest so I felt quite desperate. Now the connexion is back, first thing I did was to actualize avast and tried to scan from reboot, but it mantains in a 0% (altough it's apparently working). I tried doing it from the computer while it was on, but I had the same problem. I don't think my PC is damaged, cause it seems to work alright (a little bit slower) but I'm worried about that trojan...Is there any chance the virus has altered the avast program? I though the first thing that would happen when I finally got connected would be an avast alarm adverting me about this new virus, but that hasn't happened. Does anybody know what's happened? Should I install a new version of avast? Thanx in advance!

[CharleyO]

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You might first try a repair of avast through Add/Remove programs.

Perhaps someone else has a better suggestion.


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[Lisandro]

Is there any chance the virus has altered the avast program?

Some virus can corrupt antivirus installation. Avast 4.8 has a self-defense module.

I though the first thing that would happen when I finally got connected would be an avast alarm adverting me about this new virus, but that hasn't happened.

If you couldn't move to Chest, what did you do?
I suggest:

1. Disable System Restore and reenable it after step 3.
2. Clean your temporary files.
3. Schedule a boot time scanning with avast with archive scanning turned on.
4. Use SUPERantispyware and/or Spyware Terminator to scan for spywares and trojans. If any infection is detected, better and safer is send the file to Quarantine than to simple delete than.
5. Test your machine with anti-rootkit applications. I suggest avast! antirootkit or Trend Micro RootkitBuster.
6. Make a HijackThis log to post here or, better, submit the RunScanner log to to on-line analysis.
7. Immunize your system with SpywareBlaster or Windows Advanced Care.
8. Check if you have insecure applications with Secunia Software Inspector.