Analysis by: RonJay Kristoffer Caragay
ALIASES:

Worm:VBS/Agent.B (Microsoft); VBS.Runauto (Symantec); W32/Autom-A (Sophos); Virus.VBS.Small.a (Kaspersky); VBS/Autorun.RU!tr (Fortinet); VBS:Small-BO [Trj] (Avast); VBS/Small.A (AVG)

 PLATFORM:

Windows

 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 via removable drives. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 1,368 bytes
File Type: VBS
Memory Resident: No
Initial Samples Received Date: 09 Sep 2006

Arrival Details

This worm arrives via removable drives.

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:

  • %System%\autorun.vbs

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Propagation

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

  • {Drive Letter}:\autorun.vbs

  SOLUTION

Minimum Scan Engine: 7.500
FIRST VSAPI PATTERN FILE: 3.736.06
FIRST VSAPI PATTERN DATE: 09 Sep 2006
VSAPI OPR PATTERN File: 3.737.00
VSAPI OPR PATTERN Date: 10 Sep 2006

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Scan your computer with your Trend Micro product to delete files detected as VBS_AUTORUN.A. 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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