BKDR_MOUDOOR.AC

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.

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:

• %User Temp%\VPTray.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.)

It drops the following files:

• %User Temp%\up.bak

(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 adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
SymantecUpdate = "%User Temp%\VPTray.exe"

Other Details

This backdoor connects to the following possibly malicious URL:

• {BLOCKED}.{BLOCKED}.78.132

NOTES:

The above-mentioned autorun registry's data is coded in hex values.

This backdoor deletes all registry entries under:

• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

This registry key is one of registry locations that contain entries for applications that are executed on system start-up.