Analysis by: Sabrina Lei Sioting
 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 executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 16,896 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 25 Mar 2011
Payload: Connects to URLs/IPs, Downloads files

Installation

This Trojan drops and executes the following files:

  • %System%\mlcqdcsk.dll - detected by Trend Micro as TROJ_DLOADR.TLG

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}.{BLOCKED}.220.52/lol2.exe - detected by Trend Micro as TROJ_FAKEAV.SAF
  • http://{BLOCKED}.{BLOCKED}.220.52/pod.exe - detected by Trend Micro as WORM_AUTORUN.CFH
  • http://{BLOCKED}.{BLOCKED}.220.52/spm.exe - also detected as TROJ_BREDO.ASH

It saves the files it downloads using the following names:

  • %System Root%\Documents and Settings\Administrator\Local Settings\Temp\spm.exe - also detected as TROJ_BREDO.ASH

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}myqeg.com/1017000413
  • http://{BLOCKED}.{BLOCKED}.193.20/service/listener.php?affid=50039
  • http://{BLOCKED}.{BLOCKED}.193.20/service/scripts/files/aff_50039.dll
  • http://{BLOCKED}.{BLOCKED}.193.20/service/listener.php?affid=50039
  • http://{BLOCKED}.{BLOCKED}.88.10//srv
  • http://{BLOCKED}.{BLOCKED}.88.10//dll
  • http://{BLOCKED}.{BLOCKED}.193.20/service/scripts/files/aff_50039.dll
  • http://{BLOCKED}.{BLOCKED}.193.138/xxxx_2/MDUwNTZjMDA4fDUwMDM5fDB8M3wxZTd8NS4xIDI2MDAgU1AzLjB8MHwwfHBybjE0

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.925.00
VSAPI OPR PATTERN Date: 25 Mar 2011

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_BREDO.ASH

    • TROJ_DLOADR.TLG
    • TROJ_FAKEAV.SAF
    • WORM_AUTORUN.CFH

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_BREDO.ASH. 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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