Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 98, ME, NT, 2000, XP, Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This worm 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: 24,576 bytes
File Type: PE
Memory Resident: No

Installation

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

  • %system%\drivers\svchost.exe

It drops the following file(s)/component(s):

  • %User Temp%\rs.bat

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

Propagation

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

  • setup.exe

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=setup.exe
shellexecute=setup.exe
shell\Auto\command=setup.exe

  SOLUTION

Minimum Scan Engine: 8.900

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

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result. %User Temp%\rs.bat

Step 3

Scan your computer with your Trend Micro product to delete files detected as WORM_OTORUN.DR. 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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