Analysis by: Janus Agcaoili
ALIASES:

a variant of Win32/HackTool.Patcher.AD potentially unsafe (ESET-NOD32), Win32:Patcher-AK [PUP] (Avast), RiskWare.FilePatcher (Malwarebytes)

 PLATFORM:

Windows

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

  • Threat Type: Hacking Tool

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This hacking tool arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be manually installed by a user.

It uses a user interface (UI).

  TECHNICAL DETAILS

File Size: 62,976 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 06 Dec 2016
Payload: Displays windows

Arrival Details

This hacking tool arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It may be manually installed by a user.

Installation

This hacking tool drops and executes the following files:

  • %User Temp%\dup2patcher.dll <- responsible for the patching, will be deleted after execution

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other Details

This hacking tool uses the following user interface:

It does the following:

  • Displays a GUI for the user to interact with.
  • Patches the following file(s) to disable the "Plugin Restrictions of Mozilla Firefox v45" when the "Patch" button is clicked:
    • {Mozilla Firefox Directory}\xul.dll
    Note: If the patcher is not within the Firefox Directory, the user is given the option to search for the "xul.dll" file manually
  • Displays a message in the GUI of either the successful or failed patching of the target file.

  SOLUTION

Minimum Scan Engine: 9.800
SSAPI PATTERN File: 1.791.00
SSAPI PATTERN Date: 08 Dec 2016

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Identify and terminate files detected as HKTL_PATCHFOX.GA

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Search and delete this file

[ 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.  %User Temp%\dup2patcher.dll

Step 5

Scan your computer with your Trend Micro product to delete files detected as HKTL_PATCHFOX.GA. 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 6

Restore deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    {Mozilla Firefox Directory}.xul.dll


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