Analysis by: Anthony Joe Melgarejo
ALIASES:

Exploit:Java/Blacole.GS (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 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.

It downloads a file from a certain URL then renames it before storing it in the affected system. It takes advantage of software vulnerabilities to allow a remote user or malware/grayware to download files.

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

  TECHNICAL DETAILS

File Size: Varies
File Type: Java Class
Initial Samples Received Date: 30 Oct 2012
Payload: Downloads files

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.

Download Routine

This Trojan downloads files from the following URLs then renames them before storage in the affected system:

  • http://{URL}?asd=12gqw

It takes advantage of the following software vulnerabilities to allow a remote user or malware/grayware to download files:

  • CVE-2012-1723

It saves the files it downloads using the following names:

  • %User Temp%\awt43abr.exe
  • %User Temp%\berstrestvers.exe
  • %User Temp%\bawt34tv.exe
  • %User Temp%\tab4vrtve.exe
  • %User Temp%\wgsdgsdgdsgsd.exe
  • %User Temp%\ab43yctewatv.exe
  • %User Temp%\a43vtzgbdgv.exe
  • %User Temp%\atv4tvq34.exe
  • %User Temp%\bg34dfbewgba4.exe
  • %User Temp%\av4a43by4ayb.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:

Where {URL} is passed by the loaded resource of okmokmokmoka.class.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.496.09
FIRST VSAPI PATTERN DATE: 30 Oct 2012
VSAPI OPR PATTERN File: 9.497.00
VSAPI OPR PATTERN Date: 31 Oct 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

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

Step 4

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.  

  • http://www.oracle.com/technetwork/topics/security/javacpujun2012-1515912.html


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