W32/MitGlieder.D!tr

Alias/esW32/Bagle.L, W32/MitGlieder.D!tr, WORM_BAGLE.L
Release DateMay 12, 2006
Detection Availability
Active DatabaseExtended Database
FortiGatelowhigh
FortiClient
FortiMailN/A
Current Antivirus Definition Database Version: 12.323
Description

Visible Symptoms

  • Possible firewall alert that the infected system is attempting to access the Internet using TCP port 11117

  • Creation of these files into the System32 folder -

    system.exe - 19,968 bytes
    irun4.exe - 14,848 bytes
    iinj4.exe - 1,536 bytes
    ban_list.txt - 4,100+ bytes

  • Web traffic logs have reference to the web file "ngr2.php" and "banlist.php"


Detailed Analysis


Specifics
Trojan is 32-bit and is a very variant of W32/Mitglieder.C-tr. The Mitglieder Trojan and the Bagle virus families share some code and structure. This Trojan functions as an SMTP mail relay on a compromised system.


Loading At Windows Startup
If the Trojan is run, it will extract other files and store them into the System32 folder -

C:\WINNT\Sytem32\system.exe - dropper for Mitglieder.D
C:\WINNT\System32\irun4.exe - Mitglieder.D
C:\WINNT\System32\iinj4.exe - loader for Mitglieder.D

The Trojan will adjust the registry to auto run the Trojan at next Windows startup as in this example -

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\
"ssgrate.exe" = C:\WINNT\System32\irun4.exe


Application Termination Payload
This Trojan may attempt to close processes or applications matching the following names -

ATUPDATER.EXE
AUPDATE.EXE
AUTODOWN.EXE
AUTOTRACE.EXE
AUTOUPDATE.EXE
AVLTMAIN.EXE
AVPUPD.EXE
AVWUPD32.EXE
AVXQUAR.EXE
CFIAUDIT.EXE
DRWEBUPW.EXE
ICSSUPPNT.EXE
ICSUPP95.EXE
LUALL.EXE
MCUPDATE.EXE
NUPGRADE.EXE
OUTPOST.EXE
UPDATE.EXE


SMTP Proxy/Remote Access Capability
This Trojan will bind to TCP port 11117 and await instructions from a malicious user. Instructions could be to carry out SMTP delivery via the Trojan's SMTP proxy code.

The Trojan will attempt to notify the Trojan author by connecting to compromised web servers and using a server-side script named "ngr2.php", the Trojan will submit the TCP port in use and the IP address of the compromised system. The Trojan author compromised several German and Russian websites and probably has at least read access to these sites in order to retrieve the logged IP addresses of compromised systems.

These are the list of compromised web servers and directory paths which are storing the server-side script "ngr2.php" -

http://alfinternational.ru/old/oli-lack_katalog/
http://artesproduction.com/
http://comdat.de/kreta/
http://gaz-service.ru/img/pict/
http://mir-auto.ru/
http://rdwufa.ru/img/pict/
http://www.bbszene.de/store/images/video_amazon/
http://www.ctn.ru/marketing/images/
http://www.deadlygames.de/DG/BF/BF-Links/clans/
http://www.eurostretch.ru/
http://www.gasterixx.de/gfx/
http://www.gebr-wachs.de/mod/san_beratung/thumb/
http://www.hhc-online.de/home/links/pics/
http://www.joerrens.de/system/include/crc.php
http://www.komandor.ru/sessions/
http://www.lords-of-havoc.de/Avatare/
http://www.lowenbrau.ru/manager_old/images/
http://www.mirage.ru/sport/omega/pic/omega/
http://www.o-problemo.de/gaestebuch/
http://www.psnr.ru/rus/images/banners/
http://www.ranknet.de/LVS/pics/_notes/
http://www.tv87.de/subdomain_la/Fachwart/

The Trojan also will retrieve a text file named "banlist.php" containing IP addresses. This PHP file is stored on these compromised web servers -

http://alfinternational.ru/old/oli-lack_katalog/
http://gaz-service.ru/img/pict/
http://rdwufa.ru/img/pict/
http://www.ctn.ru/marketing/images/
http://www.komandor.ru/sessions/
http://www.lowenbrau.ru/manager_old/images/
http://www.mirage.ru/sport/omega/pic/omega/
http://www.psnr.ru/rus/images/banners/

The PHP file "banlist.php" is stored into the System32 folder with the proxy Trojan as the file name "ban_list.txt".

The Trojan makes additional registry entries which are used by the Trojan -

HKEY_CURRENT_USER\Software\DateTime
"port" = 6D, 2B, 00, 00 <= hex for TCP port '11117'
"r4dr" = 01, 00, 00, 00 <= binary for 'yes'
"uid" = [time of infection, in seconds since Jan 1 1970 00:00]



Description Last Updated Date: Mar 13, 2007
Reference: ID - 2158