Analysis by: Mark Joseph Manahan
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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 connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats.

  TECHNICAL DETAILS

File Size: 57,856 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 31 May 2012

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.

Download Routine

This Trojan connects to the following malicious URLs:

  • http://{BLOCKED}.{BLOCKED}.170.182/722505.html

NOTES:

It drops multiple copies of non-malicious files in the following format:

  • %User Temp%\~!{random number or letter}.tmp

(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.. %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.)

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.176.02
FIRST VSAPI PATTERN DATE: 07 Jun 2012
VSAPI OPR PATTERN File: 9.177.00
VSAPI OPR PATTERN Date: 08 Jun 2012

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

Identify and terminate files detected as TROJ_AGENT.BCOU

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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.
  • %User Temp%\~!{random number or letter}.tmp

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT.BCOU. 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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