TROJ_ZBOT.WAH

This Trojan checks for the presence of the following processes which are related to Outpost Personal Firewall and ZoneLabs Firewall Client. It terminates if either of the said processes exist. This is to ensure that it runs uninterrupted.

Installation

This Trojan drops copies of itself in the Windows system folder and appends garbage code to the dropped copy to avoid easy detection. The dropped copies uses the following file names:

• ntos.exe

It drops the following non-malicious files:

• %System%\wsnpoem\audio.dll - used to save the gathered information
• %System%\wsnpoem\video.dll - copy of the encrypted downloaded file

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It creates the following folders with attributes set to System and Hidden to prevent users from discovering and removing its components:

• %System%\wsnpoem

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

• __SYSTEM__91C38905__

It injects itself into the following processes as part of its memory residency routine:

• WINLOGON.EXE
• SVCHOST.EXE

Autostart Technique

This Trojan modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = %System%\Userinit.exe,%System%\ntos.exe

(Note: The default value data of the said registry entry is %System%\Userinit.exe,.)

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Network
UID = {computer name}_{random numbers}

Information Theft

This Trojan accesses the following site to download its configuration file:

• http://from-us-with-love.info/imglov/zmpt4d/n16v18.bin

Stolen Information

This Trojan saves the stolen information in the following file:

• %System%\wsnpoem\audio.dll

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Other Details

This Trojan did not exhibit propagation routines during testing.

It checks for the presence of the following processes, which are related to Outpost Personal Firewall and ZoneLabs Firewall Client:

• outpost.exe
• zlclient.exe

It did not exhibit backdoor routines during testing.