Analysis by: Cris Nowell Pantanilla
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This worm arrives via removable drives.

It drops copies of itself in all removable and physical drives found in the system.

  TECHNICAL DETAILS

File Size: 1,348,164 bytes
File Type: VBS
Memory Resident: Yes
Initial Samples Received Date: 09 Jan 2012

Arrival Details

This worm arrives via removable drives.

Installation

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

  • %System%\Folder.vbs

(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.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,%System%\wscript.exe %System%\Folder.vbs"

(Note: The default value data of the said registry entry is "%System%\userinit.exe,".)

Propagation

This worm drops copies of itself in all removable and physical drives found in the system.

NOTES:
It searches for folders in all physical and removable drives then drops copies of itself inside the folder as {folder name}.vbs.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.698.05
FIRST VSAPI PATTERN DATE: 09 Jan 2012
VSAPI OPR PATTERN File: 8.699.00
VSAPI OPR PATTERN Date: 10 Jan 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and delete files detected as VBS_MILGOTIE.B using either the Startup Disk or Recovery Console

[ Learn More ]

Step 3

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Userinit = "%System%\userinit.exe,%System%\wscript.exe %System%\Folder.vbs"
      To: Userinit = "%System%\userinit.exe,"

Step 4

Scan your computer with your Trend Micro product to delete files detected as VBS_MILGOTIE.B. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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