Analysis by: Abraham Latimer Camba

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

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 does not have any propagation routine.

It does not have any backdoor routine.

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. As of this writing, the said sites are inaccessible.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size: 151,552 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 20 Jun 2012
Payload: Connects to URLs/IPs, Drops files

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 non-malicious file:

  • %User Profile%\Application Data\Microsoft\Crypto\DSS\{User SID}\{hex values}

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan connects to the following malicious URLs:

  • {BLOCKED}.{BLOCKED}.198.112/microsoft/errorpost/default/connect.aspx?ID={random digits}
  • {BLOCKED}.{BLOCKED}.198.112/microsoftupdate/getupdate/default.aspx?ID={random digits}para1={random digits}para2={random digits}para3={random digits}

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan does not have any information-stealing capability.

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerabilities.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.216.02
FIRST VSAPI PATTERN DATE: 25 Jun 2012
VSAPI OPR PATTERN File: 9.217.00
VSAPI OPR PATTERN Date: 26 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.PSH

[ 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 Profile%\Application Data\Microsoft\Crypto\DSS\{User SID}\{hex values}

Step 4

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