Analysis by: Marfel Tiamzon
ALIASES:

Microsoft: Exploit:Java/CVE-2010-0840.CD; Kaspersky: Trojan-Downloader.Java.OpenConnection.du

 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 arrives as a component bundled with malware/grayware packages. It executes when a user accesses certain websites where it is hosted.

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

  TECHNICAL DETAILS

File Size: Varies
File Type: Java Class
Memory Resident: No
Initial Samples Received Date: 05 Oct 2011

Arrival Details

This Trojan arrives as a component bundled with malware/grayware packages.

It executes when a user accesses certain websites where it is hosted.

Download Routine

This Trojan saves the files it downloads using the following names:

  • %User Temp%\{random number}.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.

NOTES:

It arrives via a malicious Java Archive (JAR) file. This obfuscated Java applet is used to download and execute possibly malicious file from the domain where it is hosted.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.474.01
FIRST VSAPI PATTERN DATE: 05 Oct 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

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 number}.exe

Step 4

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