VBS_DUNIHI.AB

 Analysis by: Vincent Martin Hermosura

 ALIASES:

Worm:VBS/Dunihi.A (Microsoft), Trojan.Script.Suspic.gen (Kaspersky), JS/Heur (AVG), VBS/Agent.NDE worm (NOD32)

 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 drops copies of itself in the Windows Common Startup folder to enable its automatic execution at every system startup.

It drops copies of itself into all the removable drives connected to an affected system.

  TECHNICAL DETAILS

File Size:

9,404 bytes

File Type:

VBS

Installation

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

  • %Application Data%\{malware name}.vbs

(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.)

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
{malware name} = "wscript.exe //B %Application Data%\{malware name}.vbs"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{malware name} = "wscript.exe //B %Application Data%\{malware name}.vbs"

It drops copies of itself in the Windows Common Startup folder to enable its automatic execution at every system startup.

Propagation

This worm drops copies of itself into all the removable drives connected to an affected system.

NOTES:

This malware sets the attributes of its dropped copie(s) in removable drives to Hidden and System.