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 does not have any propagation routine.

It does not have any backdoor routine.

It modifies the Internet Explorer Zone Settings.

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.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 31,744 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 06 Dec 2011
Payload: Connects to URLs/IPs

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 copies of itself into the affected system:

  • %User Startup%\dxdiag.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

It injects itself into the following processes as part of its memory residency routine:

  • svchost.exe

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Download Routine

This Trojan connects to the following malicious URLs:

  • http://{BLOCKED}morrow.com/banners/task.php?bid=0df005f0ac8dec80&os=5-1-2600&uptime=0&rnd=3128953

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan deletes the initially executed copy of itself

NOTES:

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.626.02
FIRST VSAPI PATTERN DATE: 06 Dec 2011
VSAPI OPR PATTERN File: 8.627.00
VSAPI OPR PATTERN Date: 06 Dec 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

Restart in Safe Mode

[ Learn More ]

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 Startup%\dxdiag.exe

Step 4

Reset Internet security settings

[ Learn More ]

Step 5

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