BKDR_NITOL.GD

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 connects to a website to send and receive information.

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.

Installation

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

• %System%\{random}.exe
• %System%\hra33.dll

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

It drops the following files:

• %User Temp%\{random}.tmp
• %User Temp%\SOFTWARE.LOG

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Autostart Technique

This backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribumkq
ImagePath = "%System%\{random}.exe"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribumkq

Backdoor Routine

This backdoor connects to the following websites to send and receive information:

• {BLOCKED}35.3322.org

NOTES:

It drops the following copy of itself in all folders and RAR archives in all physical and removable drives containing an EXE file:

• lpk.dll