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Aliases :

Mitglieder.AI, I-Worm.Bagle.v, TrojanProxy.Win32.Mitglieder.AI, W32/Mitglieder.AI, W32/Bagle.x!proxy


A new Mitglieder proxy trojan appeared on April 7th 2004. It installs itself to system and works as a mail relay on port 14247. The trojan connects to several websites to report its port and ID. Similar Mitglieder trojan variants were dropped by certain Bagle worms in the past.


Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

The Mitglieder.AI's file is a PE executable 7824 bytes in size packed with FSG file compressor.

According to our partner, the trojan was spammed in email messages that had the following text:

We agree with your terms. The deal is acceptable.
For more information please read attached document.
 Thank you.
Lisa Marlow.

When the trojan's file is run, it copies itself as WINDOW.EXE file to Windows System folder and creates a startup key for this file in the Registry:

"window.exe" = "%winsysdir%\window.exe"

where %winsysdir% represents Windows System folder name.

Then the trojan opens a backdoor on port 14247, listens for remote commands and works as a mail relay. The trojan connects to several websites to report infected computer's IP address, ID and proxy port.

This Mitglieder variant doesn't kill processes of security and anti-virus software.