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:

  • In the wild: Yes

  OVERVIEW

This Trojan may arrive bundled with malware packages as a malware component. It may be hosted on a website and run when a user accesses the said website.

  TECHNICAL DETAILS

File Size: Varies
File Type: Java Class
Initial Samples Received Date: 03 May 2012

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

It may be hosted on a website and run when a user accesses the said website.

NOTES:

It is a component of a malicious Java archive file (.JAR) that is hosted in a malicious web site.

Depending on the current user's permission set, this Java Class attempts to download possibly malicious files from a certain web site.

The download link depends on where the malicious Java Class is hosted.

The downloaded file is usually saved as %User Temp%\{random file name}.exe.

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

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.972.01
FIRST VSAPI PATTERN DATE: 04 May 2012
VSAPI OPR PATTERN File: 8.973.00
VSAPI OPR PATTERN Date: 05 May 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

Close all opened browser windows

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 file name}.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as JAVA_DLOADER.IRM. 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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