Analysis by: Michael Cabel
ALIASES:

Sophos: Troj/JsDldr-C

 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 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.

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

  TECHNICAL DETAILS

File Size: 14,739 bytes
File Type: JS
Memory Resident: No
Initial Samples Received Date: 22 Dec 2010

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 saves the files it downloads using the following names:

  • %Application Data%\wert3.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data 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 attempts to access the following websites to download files, which are possibly malicious:

  • http://{BLOCKED}.{BLOCKED}.162.176/dm6.exe

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.719.00
VSAPI OPR PATTERN Date: 22 Dec 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 JS_DLOADR.HB. 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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