BKDR_ZEGOST.AZ

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be dropped by other malware.

It does not have any propagation routine.

It opens a hidden Internet Explorer window. It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

It does not have any downloading capability.

It does not have any information-stealing capability.

It deletes the initially executed copy of itself.

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It may be dropped by the following malware:

• TROJ_ARTIEF.CK

Installation

This backdoor drops the following copies of itself into the affected system and executes them:

• %User Temp%\1111111.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

It drops the following component file(s):

• %User Temp%\00
• %User Temp%\1111111.dll - detected as BKDR_ZEGOST.AZ
• %User Temp%\config.txt - contains the encrypted remote address

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

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

• 1111111 Is Running!

Autostart Technique

This backdoor drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

• %User Startup%\xxxxxxxx.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor opens a hidden Internet Explorer window.

It executes the following commands from a remote malicious user:

• Perform remote shell commands

It connects to the following websites to send and receive information:

• http://{BLOCKED}0.{BLOCKED}0.35.60:2002
• https://{BLOCKED}0.{BLOCKED}0.35.60:2002

Download Routine

This backdoor does not have any downloading capability.

Information Theft

This backdoor does not have any information-stealing capability.

Other Details

This backdoor deletes the initially executed copy of itself

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerability.