Analysis by: Rika Joi Gregorio

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit), Mac OS, Unix, Linux

 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 malware was downloaded from a fake Trend Micro page.

This Trojan may arrive bundled with malware packages as a malware component. It may be unknowingly downloaded by a user while visiting malicious websites. It may be hosted on a website and run when a user accesses the said website.

  TECHNICAL DETAILS

File Size: 4,572 bytes
File Type: Java, Java Class
Initial Samples Received Date: 08 Jan 2013
Payload: Drops files, Downloads files

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

It may be unknowingly downloaded by a user while visiting malicious websites.

It may be hosted on a website and run when a user accesses the said website.

It may be downloaded from the following remote sites:

  • hxxp://{BLOCKED}e.{BLOCKED}icro-portal.com/Signed_Update.jar

Installation

This Trojan drops the following file(s)/component(s):

  • %Temp%\42logfile42.tmp - non malicious log

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)

NOTES:

This Java file is a product of Social-Engineer Toolkit (SET) used in penetration testing and advanced technological attacks in a social-engineering type environment.

This Java file is a universal applet that first determines the running OS. It then downloads a file and saves it in %User Profile%. The downloaded file is executed and as a result, malicious routines of the downloaded files are exhibited on the affected system.

The accessed ULRs can be acquired from other component files.

The downloaded files are saved as the following:

  • For Windows: {random characters}.exe
  • For Mac OS, UNIX, LINUX: {random characters}.bin

This applet should be signed in order for it to execute properly. As a signed applet, it can disguise itself as an applet or application from a reliable source and can be trusted to run with the permissions granted in the policy file.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.644.01
FIRST VSAPI PATTERN DATE: 08 Jan 2013
VSAPI OPR PATTERN File: 9.645.00
VSAPI OPR PATTERN Date: 09 Jan 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.
  • 42logfile42.tmp
  • %User Profile%\{random characters}.exe (for Windows)
  • %User Profile%\{random characters}.exe (for Mac OS, Unix, Linux)

Step 4

Scan your computer with your Trend Micro product to delete files detected as JAVA_DLOADER.DSA. 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.


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