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 downloads chunks of encoded data. Once the download is completed, it then decodes and assembles the data to form a binary file. Note that the downloaded files may vary depending on the data that have been sent.

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 79,360 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 02 Mar 2011

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_PIDIEF.FJS

Installation

This Trojan drops the following non-malicious file:

  • %User Temp%\wmiprvse.ini - contains the path where the downloaded files are stored

(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.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • HUSSARINI

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft
ServerID = "28ef4f"

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}001l.dyndns.info

It saves the files it downloads using the following names:

  • %User Temp%\ScnCfg32.Exe - nonmalicious
  • %User Temp%\vsodscpl.dll - nonmalicious

(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.)

NOTES:
It downloads chunks of encoded data. Once the download is completed, it then decodes and assembles the data to form a binary file. Note that the downloaded files may vary depending on the data that have been sent.

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.868.02
FIRST VSAPI PATTERN DATE: 02 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_DLOADR.FJS

     TROJ_PIDIEF.FJS

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft
    • ServerID = 28ef4f

Step 4

Search and delete these files

[ 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%\wmiprvse.ini
  • %User Temp%\ScnCfg32.Exe
  • %User Temp%\vsodscpl.dll

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADR.FJS. 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.


Did this description help? Tell us how we did.