BKDR_BARKIOFOR.B

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 executes commands from a remote malicious user, effectively compromising the affected system. 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 non-malicious file:

• %User Temp%\~ISUN32.exe - Cmd.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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

• File & Directory Manipulation
• List Drivers
• Reboot Machine
• Get System Information
• Remote Command Shell
• Download and Execute Files
• Upload Files
• Load Additional Plugins

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

• update.{BLOCKED}e.{BLOCKED}s.com:443
• update.{BLOCKED}e.{BLOCKED}s.com:80

Download Routine

This backdoor connects to the following URL(s) to download its component file(s):

• http://{BLOCKED}.{BLOCKED}.70.155:80/microsoft/product/windows/update/asp?{value}

Other Details

This backdoor requires the following additional components to properly run:

• {Malware Path}\msd3.dat
• %System%\drivers\rio16drv.sys
• {Malware Path}\msxml.log

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