WORM_DORKBOT.PSU

 Analysis by: Nikko Tamana

 ALIASES:

W32/Dorkbot.AS!tr (Fortinet), Worm.Win32.Ngrbot.scq (Ikarus), VirTool:Win32/Binder (Microsoft)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This worm arrives by connecting affected removable drives to a system. 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 executes then deletes itself afterward.

  TECHNICAL DETAILS

File Size:

181,760 bytes

File Type:

EXE

Initial Samples Received Date:

28 Nov 2013

Arrival Details

This worm arrives by connecting affected removable drives to a system.

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 worm drops the following copies of itself into the affected system:

  • %Application Data%\{random file name}.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It executes then deletes itself afterward.

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random file name}.exe"

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • {removable drive letter}:\{random}.exe

Other Details

This worm connects to the following URL(s) to get the affected system's IP address:

  • http://api.wipmania.com

It connects to the following possibly malicious URL:

  • {BLOCKED}e.{BLOCKED}c.net

NOTES:

It drops shortcut files pointing to the copy of itself in removable drives. These dropped .LNK files use the names of the folders and files located on the said drives for their file names. It then sets the attributes of the original folders and files to Hidden to trick the user into clicking the .LNK files.