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JAVA_BLACOLE.KL

June 15, 2013
 Analysis by: Rika Joi Gregorio
 ALIASES:

Exploit:Java/CVE-2012-1723(Microsoft), Exploit.Java.CVE-2012(Ikarus)

 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:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

Java Class

Initial Samples Received Date:

06 Jun 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 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:

  • RluWYitWd
  • OsYSu
  • JsSesgKUF

Other Details

This Trojan executes the downloaded file using the following commands:

  • regsvr32 -s "%User Temp%\{random file name}.exe"
  • %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:

9.982.05

FIRST VSAPI PATTERN DATE:

14 Jun 2013

VSAPI OPR PATTERN File:

9.983.00

VSAPI OPR PATTERN Date:

15 Jun 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 these files

[ Learn More ]
There may be some 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_BLACOLE.KL. 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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