Analysis by: Rhena Inocencio
ALIASES:

TrojanDownloader:Java/OpenStream.CE (Microsoft), Exploit-CVE2012-1723 (McAfee), Trojan.Maljava (Symantec)

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

It requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size: 6,574 bytes
File Type: Java Class
Initial Samples Received Date: 29 Aug 2012

Arrival Details

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

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

Download Routine

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

  • %User Temp%\install_msi.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.)

Other Details

This Trojan requires its main component to successfully perform its intended routine.

NOTES:

This Trojan downloads a possibly malicious file from a certain URL. The URL where this malware downloads the said file depends on the parameter passed on to it by its components.

It executes the downloaded file using the following commands:

  • regsvr32 -s "%User Temp%\install_msi.exe"
  • %User Temp%\install_msi.exe

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.358.02
FIRST VSAPI PATTERN DATE: 29 Aug 2012
VSAPI OPR PATTERN File: 9.359.00
VSAPI OPR PATTERN Date: 30 Aug 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%\install_msi.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as JAVA_EXPLOIT.TE. 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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