Analysis by: Roland Marco Dela Paz

 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

This malware arrives on the users' systems via spammed messages that posed as invitation for The Free Supper Day.The bogus invitation supposedly came from McDonald's. It then informed users to print the invitation inside the ZIP attachment. Once users opened it, the malware is installed on their systems.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

This malware is a modular downloader. Upon execution, it reports system infection to a certain site.

The server then replies what payload to exhibit on the infected system. As of writing, the server commands the download of TROJ_CTGOG.VI and TSPY_KARAGNY.VI on the infected system.

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

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: 25,600 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 21 Jun 2011
Payload: Downloads files, Sends and receives information

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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 stays memory-resident by injecting codes into the following processes:

  • svchost.exe

Other Details

This Trojan connects to the following website to send and receive information:

  • {BLOCKED}dexchange2011.ru

NOTES:
This malware is a modular downloader. Upon execution, it reports system infection to the following site:

  • http://{BLOCKED}dexchange2011.ru/forum/task.php?bid={value}&os={value}&uptime={value}&rnd={value}

The server then replies what payload (download)to exhibit on the affected system. As of writing, the server commands the following downloads:

  • http://{BLOCKED}.61.25/forum/load.php?module=grabbers - detected as TSPY_KARAGNY.VI
  • http://{BLOCKED}dexchange2011.ru/abs.exe - detected as TROJ_CTGOG.VI

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

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 8.239.00
VSAPI OPR PATTERN Date: 22 Jun 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_INJECTOR.VI

Step 3

Scan your computer with your Trend Micro product and note files detected as TROJ_INJECTOR.VI

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

Search and delete the file detected as TROJ_INJECTOR.VI

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 6

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