Analysis by: Sabrina Lei Sioting
 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

Infection Channel: Propagates via removable drives

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: 21,035 bytes
File Type: EXE
File Compression: UPX
Memory Resident: No
Initial Samples Received Date: 05 Mar 2009
Payload: Drops files

Installation

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

  • %Program Files%\Internet Explorer\msvcrt.bak

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

Propagation

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

  • Ghost.pif

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=Ghost.pif
shellexecute=Ghost.pif
shell\Auto\command=Ghost.pif
shell=Auto

Dropping Routine

This worm drops the following files:

  • %Program Files%\Common Files\Relive.dll - detected by Trend Micro as Mal_Run-4
  • %Program Files%\Internet Explorer\msvcrt.dll - detected by Trend Micro as Mal_Run-4

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

NOTES:

The dropped AUTORUN.INF file is detected by Trend Micro as Mal_Otorun1.

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 5.883.00
FIRST VSAPI PATTERN DATE: 05 Mar 2009

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

Remove malware files dropped/downloaded by WORM_AUTORUN.FYU

    Mal_Run-4
    Mal_Otorun1

Step 3

Search and delete this file

[ 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.  %Program Files%\Common Files\Relive.dll
%Program Files%\Internet Explorer\msvcrt.dll

Step 4

Search and delete AUTORUN.INF files created by WORM_AUTORUN.FYU that contain these strings

[ Learn More ]
[autorun]
open=Ghost.pif
shellexecute=Ghost.pif
shell\Auto\command=Ghost.pif
shell=Auto

Step 5

Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.FYU. 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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