Analysis by: Erika Bianca Mendoza
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

When executed, this Trojan accesses an adult site.

This Trojan may be unknowingly downloaded by a user while visiting malicious websites. It executes when a user accesses certain websites where it is hosted.

  TECHNICAL DETAILS

File Size: 11,956 bytes
File Type: HTA
Memory Resident: No
Initial Samples Received Date: 20 Apr 2011
Payload: Connects to URLs/IPs

Arrival Details

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

It executes when a user accesses certain websites where it is hosted.

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
zack = "{malware path and file name}"

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\zack
status = "0"

NOTES:

It accesses the following adult site:

  • http://{BLOCKED}a-movie.com

  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

Scan your computer with your Trend Micro product and note files detected as TROJ_HTAPORN.VTG

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • zack = {malware path and file name}
  • In HKEY_CURRENT_USER\Software\zack
    • status = 0

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_HTAPORN.VTG. 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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