WORM_NITOL.C

 Analysis by: Rika Joi Gregorio

 ALIASES:

TROJ_BIKX

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This worm 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 then deletes itself afterward.

  TECHNICAL DETAILS

File Size:

40,960 bytes

File Type:

EXE, DLL

Memory Resident:

Yes

Initial Samples Received Date:

12 Nov 2010

Arrival Details

This worm 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 worm drops the following copies of itself into the affected system and executes them:

  • %System%\{random}.exe
  • %System%\hra33.dll

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It executes then deletes itself afterward.

Autostart Technique

This worm creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribuvbf
Type = "10"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribuvbf
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribuvbf
ErrorControl = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribuvbf
ImagePath = "%System%\{random}.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribuvbf
DisplayName = "Distribuihd Transaction Coordinator Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribuvbf
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Distribuvbf
Description = "Distribucha Transaction Coordinator Service."

Other Details

This worm connects to the following possibly malicious URL:

  • scrk.{BLOCKED}2.org

NOTES:

This worm drops the following copy of itself in all folders and .RAR and .ZIP archives in all physical and removable drives containing an EXE file:

  • lpk.dll