Analysis by: Roland Marco Dela Paz
ALIASES:

Exploit.JS.Agent.bgy (Kaspersky); Troj/ExpJS-BS (Sophos)

 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

This Trojan may be downloaded from remote sites by other malware.

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

It takes advantage of certain vulnerabilities.

  TECHNICAL DETAILS

File Size: 2,100 bytes
File Type: Java Class
Memory Resident: No
Initial Samples Received Date: 29 Apr 2011
Payload: Downloads files

Arrival Details

This Trojan may be downloaded from remote site(s) by the following malware:

  • JS_OBFUS.HB

It may be downloaded from the following remote sites:

  • http://{BLOCKED}ng.info/games/java_skyline.php

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}ng.info/d.php?f={parameter}&e={parameter} - detected as TSPY_FTPMESO.HBM

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

Other Details

More information on this vulnerability can be found below:

It takes advantage of the following vulnerabilities:

  • Vulnerability in the way the Java NPAPI plugin and the Java Deployment Toolkit handles URIs

  SOLUTION

Minimum Scan Engine: 8.900

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

Remove malware files dropped/downloaded by JAVA_EXPLOIT.HBM

Step 3

Close all opened browser windows

Step 4

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