Analysis by: Jaime Benigno Reyes
 Modified by: Nikko Tamana
ALIASES:

Exploit:Java/CVE-2013-0422 (Microsoft), Java/Agent.PKA!tr (Fortinet), a variant of Java/Exploit.Agent.PKA trojan (NOD32)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

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

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

  TECHNICAL DETAILS

File Size: Varies
File Type: Java Class
Initial Samples Received Date: 28 Aug 2013
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 takes advantage of the following software vulnerabilities to download possibly malicious files:

It saves the files it downloads using the following names:

  • %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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

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

It downloads a possibly malicious file from a certain URL. The URL where this malware downloads the said file depends on the following parameter(s) passed on to it by its components:

  • duFJfXw

Other Details

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

It executes the downloaded file using the following commands:

  • regsvr32 -s %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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.244.01
FIRST VSAPI PATTERN DATE: 28 Aug 2013
VSAPI OPR PATTERN File: 10.245.00
VSAPI OPR PATTERN Date: 29 Aug 2013

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

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_EXPLOIT.DPA. 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 5

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


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