BKDR_WINNTI.OWMT

This backdoor may arrive bundled with malware packages as a malware component. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It runs certain commands that it receives remotely from a malicious user. Doing this puts the affected computer and information found on the computer at greater risk.

It deletes the initially executed copy of itself.

Arrival Details

This backdoor may arrive bundled with malware packages as a malware component.

It 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%\KJIEJUI7A.AX

(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%\_guid.dat - contains created GUID for the infected system

(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 and executes the following files:

• %System%\metro.dll - also detected as BKDR_WINNTI.OWMT
• {variable path}\libglesv32.dll - also detected as BKDR_WINNTI.OWMT

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

It drops the following non-malicious file:

• {variable path}\wuauclt.exe - copy of legitimate rundll32.exe

Autostart Technique

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

{KEY}\Software\Microsoft\
Windows\CurrentVersion\Run
vmCheck = ""{variable path}\wuauclt.exe" "{variable path}\libglesv32.dll",vmCheck"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{service name}
Start = "2"

(Note: The default value data of the said registry entry is 3.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{service name}\Parameters
ServiceDll = "%System%\metro.dll"

(Note: The default value data of the said registry entry is {service path and file name}.)

Other System Modifications

This backdoor adds the following registry entries:

{KEY}\Software\Classes
CDrivce = "{encrypted binary data}"

{KEY}\Software\Classes
Drivce = "{SOFTRES Resource of the malware}"

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor executes the following command(s) from a remote malicious user:

• Download and load plugins - saved as %User Temp%\{random}_p.dat or %User Temp%\{username}.dat

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

• {BLOCKED}w.{BLOCKED}gle.com:8080

Other Details

This backdoor deletes the initially executed copy of itself

NOTES:

Where:

• {variable path} is:
  • %Application Data%\Microsoft (no admin rights)
  • %Program Files%\Common Files\System (with admin rights)
• {KEY} is:
  • HKEY_CURRENT_USER (no admin rights)
  • HKEY_LOCAL_MACHINE (with admin rights)
• {service name} is:
  • WmdmPmSN (for Windows version 5.1+*)
  • AppMgmt (for Windows 7)
• {service path and file name}:
  • %System%\mspmsnsv.dll (for Windows version 5.1+*)
  • %System%\appmgmts.dll (for Windows 7)

*Windows version 5.1+ are the following:

• Windows XP
• Windows XP Professional x64 Edition
• Windows Server 2003
• Windows Home Server
• Windows Server 2003 R2

Certain files and registry entries are only created when one of the following conditions occur:

1. The current user has no admin rights.
2. It failed to create the file %System%\metro.dll.
3. It is running under an OS not mentioned above.

The files and registry entries created are the following:

• Files:
  • {variable path}\libglesv32.dll
  • {variable path}\wuauclt.exe
• Registry:
  {KEY}\Software\Microsoft\Windows\CurrentVersion\Run
  vmCheck = ""{variable path}\wuauclt.exe" "{variable path}\libglesv32.dll",vmCheck"

It does not have rootkit capabilities.

It does not exploit any vulnerability.