Analysis by: Kathleen Notario
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

When executed, it takes advantage of a vulnerability in the Java Runtime Environment component in Oracle Java SE and Java for Business that allows remote attackers to execute arbitrary code via an untrusted object that extends the trusted class but has not modified a certain method. More information can be found in the following page:

After succesfully exploiting the said vulnerability, it may connect to remote URLs to download and execute possibly malicious files.

  TECHNICAL DETAILS

File Size: Varies
File Type: Java Class
Memory Resident: No
Initial Samples Received Date: 16 Oct 2010
Payload: Downloads files

Arrival Details

This Trojan may be downloaded from the following remote sites:

  • http://{BLOCKED}f.com/jwhqctcvbwgmh.jar

NOTES:
This Java archive consists of the following classes:

  • a.class - detected as JAVA_LOADER.HLL
  • b.class - detected as JAVA_LOADER.HLL
  • kavs.class - detected as JAVA_LOADER.HLL

The A.CLASS contains code that calls B.CLASS to decrypt a URL that is passed to it then downloads and executes the file. The said routine takes advantage of a vulnerability in the Java Runtime Environment component in Oracle Java SE and Java for Business that allows remote attackers to execute arbitrary code via an untrusted object that extends the trusted class but has not modified a certain method.

More information can be found in the following page:

After succesfully exploiting the said vulnerability, it may connect to remote URLs to download and execute possibly malicious files.

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.547.00
VSAPI OPR PATTERN Date: 16 Oct 2010

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

Scan your computer with your Trend Micro product to delete files detected as JAVA_LOADER.HLL. 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 3

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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