Analysis by: Sabrina Lei Sioting
 Modified by: Sabrina Sioting
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • 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 drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size: 4,940 bytes
File Type: VBS
Memory Resident: No
Initial Samples Received Date: 06 Apr 2010

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:

  • %Windows%\Thumbs.vbs

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
avctrl = "wscript.exe %Windows%\Thumbs.vbs"

Propagation

This worm drops the following copy of itself in all physical and removable drives:

  • %Windows%\Thumbs.vbs

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[autorun]
open=wscript.exe Thumbs.vbs
shell\open=Open
shell\open\Command=wscript.exe Thumbs.vbs
shell\open\Default=1
shell\explore=Explorer
shell\explore\Command=Explorer.exe

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 6.974.07
FIRST VSAPI PATTERN DATE: 06 Apr 2010

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

Delete this 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\CurrentVersion\Run
    • avctrl = "wscript.exe %Windows%\Thumbs.vbs"

Step 3

Search and delete AUTORUN.INF files created by VBS_SLOGOD.SM that contain these strings

[ Learn More ]
[autorun]
open=wscript.exe Thumbs.vbs
shell\open=Open
shell\open\Command=wscript.exe Thumbs.vbs
shell\open\Default=1
shell\explore=Explorer
shell\explore\Command=Explorer.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as VBS_SLOGOD.SM. 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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