BKDR_ANDROM.CRW

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. However, as of this writing, the said sites are inaccessible.

As of this writing, the said sites are inaccessible.

It deletes itself after execution.

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:

• %ProgramData%\explorer.exe (Windows Vista and 7 only)
• %All Users Profile%\explorer.exe
• %All Users Profile%\{random}.exe

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).. %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

It stays resident in memory by creating the following process(es):

• msiexec.exe

It injects codes into the following process(es):

• msiexec.exe

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Start WingMan Profiler = "%All Users Profile%\explorer.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
540 = "%All Users Profile%\{random}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Start WingMan Profiler = "%ProgramData%\explorer.exe" (Windows Vista and 7 only and if Java update is disabled in startup)

Other System Modifications

This backdoor creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "{malware path and file name}:*:Enabled:{malware file name}"

Backdoor Routine

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

• Download a file from C&C server and save it as %User Temp%\{random number}.exe
• Download a file from C&C server and save it as %System Root%\Documents and Settings\All Users\ms{random number}.dat and loads it
• Start a process
• Uninstall itself
• Remote command prompt

(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.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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

• http://{BLOCKED}dow.com/hour.php
• http://{BLOCKED}b.su/beta.php
• http://{BLOCKED}s.com/york.php
• http://{BLOCKED}i.su/abs.php

However, as of this writing, the said sites are inaccessible.

Download Routine

This backdoor accesses the following websites to download files:

• http://{BLOCKED}iobinefar.es/also.exe

It saves the files it downloads using the following names:

• %User Temp%\{random number}.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.)

As of this writing, the said sites are inaccessible.

Other Details

This backdoor deletes itself after execution.

NOTES:

This backdoor checks if it is being run in VMWare environment or emulation software. If it is being run in any of the aforementioned environments, it performs another routine where in it opens port 3232 and listens for a backdoor command to perform remote shell execution.