JAVA_DLOADER.A

October 08, 2012
 Analysis by: Christopher Daniel So
 ALIASES:

TrojanDownloader:Java/OpenConnection.HH (Microsoft), Trojan-Downloader.Java.OpenStream.as (Kaspersky), Java.Trojan.Downloader.OpenConnection.AH (FSecure), Mal/JavaKC-H (Sophos)

 PLATFORM:

Windows 2000, XP, 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 unknowingly downloaded by a user while visiting malicious websites.

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

  TECHNICAL DETAILS

File Size:

5,819 bytes

File Type:

Java Class

Memory Resident:

No

Initial Samples Received Date:

15 Dec 2010

Payload:

Downloads files

Arrival Details

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

Download Routine

This Trojan saves the files it downloads using the following names:

  • %User Temp%\{random number}.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.)

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

Other Details

This Trojan does the following:

  • It downloads the file specified the URL, from the applet parameter data.
  • It arrives via a malicious Java Archive (JAR) file.

  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

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 number}.exe

Step 4

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