BKDR_BREUT.A

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 accesses websites to download files. This action allows this malware to possibly add other malware on the affected computer. As of this writing, the said sites are inaccessible.

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:

• %User Temp%\Google Cache.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.)

Backdoor Routine

This backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:

• {BLOCKED}6.{BLOCKED}6.0.28

Dropping Routine

This backdoor drops the following files:

• %User Startup%\(Empty).lnk - shortcut file pointing to copy of itself

(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.)

Download Routine

This backdoor accesses websites to download the following files:

• http://{BLOCKED}6.{BLOCKED}.0.28/Update/Update.bin
• http://{BLOCKED}6.{BLOCKED}.0.28/Update/Update2.bin

It saves the files it downloads using the following names:

• %User Temp%\_%MpsXNpCnns.bin
• %Current%\_$sbinLop.bin
• %Current%\_$NosTsh.bin
• %Current%\Temp.bin

(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.)

As of this writing, the said sites are inaccessible.