Analysis by: Michael Cabel
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size: 146,738 bytes
Memory Resident: No
Initial Samples Received Date: 07 Oct 2008

Arrival Details

This Trojan 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 Trojan drops the following component file(s):

  • %User Temp%\colege.exe - also detected as TROJ_DLOADR.WH

(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.)

It drops the following non-malicious file:

  • %User Temp%\dw.exe

(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.)

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}3.30.103.248/images/{BLOCKED}dor.gif
  • http://{BLOCKED}3.30.103.248/images/{BLOCKED}or2.gif
  • http://{BLOCKED}3.{BLOCKED}ting.net/.counter/gid/counter.php - inaccessible

It saves the files it downloads using the following names:

  • %User Temp%\{User Name}.tmp
  • %User Temp%\antimalware.exe - detected as TROJ_FAKEAV.FWM
  • %User Temp%\hercules.exe - detected as TROJ_BANKER.RJX

(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.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 5.582.02
FIRST VSAPI PATTERN DATE: 07 Oct 2008
VSAPI OPR PATTERN File: 5.583.00
VSAPI OPR PATTERN Date: 08 Oct 2008

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 TROJ_DLOADR.WH

    • TROJ_FAKEAV.FWM
    • TROJ_BANKER.RJX

Step 3

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DLOADR.WH. 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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