[Resolved] Antivirus shows mst123.dll risk

I recently updated my Norton and then received an alert shortly after of a threat with my mst123.dll file. I believe that this is a common Windows file, so I am unsure of why it being assessed as a risk… I did a basic google search and found nothing concerning malware; the threat database at the Norton site also turned up nothing, so I am starting to think that it is a false alert by Norton. Has anyone experienced this problem? If it's relavent, I've also been experiencing an increase (up from basically 0) in popups when using IE, don't know if this is related though…

UPDATE: I did a system restore to Wednesday (before I updated Norton and started getting the alerts) to see if this cleared anything up. I did a custom scan of the system32 folder and it found nothing. Then I updated Norton again, ran the same scan, and it is identifying the mst123.dll file as a "Downloader".

UPDATE: The most recent autoscan from Norton says that it was able to partially remove the file. I went in to the system32 folder and could not find the file there, and the manual scan I ran did not find it.

Hi ac83090,



My name is Tomk. I would be glad to take a look at your log and help you with solving any malware problems. HijackThis logs can take a while to research, so please be patient and I'd be grateful if you would note the following:

• I will be working on your Malware issues, this may or may not, solve other issues you have with your machine.
• The fixes are specific to your problem and should only be used for the issues on this machine.
• Please continue to review my answers until I tell you your machine appears to be clear. Absence of symptoms does not mean that everything is clear.
• It's often worth reading through these instructions and printing them for ease of reference.
• If you don't know or understand something, please don't hesitate to say or ask!! It's better to be sure and safe than sorry.
• Please reply to this thread. Do not start a new topic.

Download HijackThis from Here .

• If using Internet Explorer, Please select RUN
• If Using Firefox, Download to your Desktop and then Double-Click on Icon to start installation.
• Choose the default location of C:\Program Files\Trend Micro\HijackThis as the destination. HJT needs to be in its own folder so that the program itself isn't deleted by accident. Having the backups could be VITAL to restoring your system if something went wrong in the FIX process!
• Click the Install button.
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• Click Do a system scan and save a log file. A Notepad file will open.
• To post the text, first you must highlight the entire text and then press the (Ctrl+C) keys which copies it to your clipboard.
• Now paste the log into this thread using the (Ctrl + V) buttons.

DO NOT MAKE ANY CHANGES OR CLICK "FIX CHECKED" UNTIL WE CHECK THE LOG, AS MOST OF THE FILES ARE LEGIT AND VITAL TO THE FUNCTION OF YOUR COMPUTER

I actually think that the problem was resolved. Norton says it fixed the problem and there were no other signs of malware on the computer. My father also does this stuff for a living and he said everything sounds fine. Thanks anyway!

ac83090, Glad to hear you got everything taken care of. Good Luck and Be Well.

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