Analysis by: Kyle Philippe Yu
ALIASES:

GT:VB.Honolulu.1.D6F3B9D8 (BITDEFENDER)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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

It drops files as ransom note.

  TECHNICAL DETAILS

File Size: 47,018 bytes
File Type: VBS
Memory Resident: Yes
Initial Samples Received Date: 24 Apr 2023
Payload: Connects to URLs/IPs, Displays message/message boxes, Encrypts files

Arrival Details

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

Installation

This Ransomware drops the following files:

  • %AppDataLocal%\GFp0JAk\GFp0JAk.vbs
  • %AppDataLocal%\GFp0JAk\GFp0JAk.exe
  • %AppDataLocal%\GFp0JAk\lLT8PCI.js
  • %AppDataLocal%\GFp0JAk\{6 Random Characters}.key
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\fs.js
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\package.json
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\graceful-fs.js
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\legacy-streams.js
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\polyfills.js

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • “%AppDataLocal%\GFp0Jak\GFp0Jak.exe” %AppDataLocal%\GFp0Jak\lLT8PCI.js
  • %System%\cmd.exe /d /s /c “vssadmin delete shadows /All /Quiet”
  • %System%\cmd.exe /d /s /c “tasklist /FI WINDOWTITLE eq Encrypt-GFp0Jak” 2>NULL | find /C /I /N “.exe””
  • taskkill /IM outlook.exe /F /T
  • taskkill /IM excel.exe /F /T
  • taskkill /IM acad.exe /F /T
  • taskkill /IM winword.exe /F /T

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Microsoft Office = %AppDataLocal%\GFp0Jak\GFp0Jak.vbs

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Startup = %AppDataLocal%\GFp0Jak\GFp0Jak.exe%AppDataLocal%\GFp0Jak\lLT8PCI.js decryptStatic

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows = cmd /c start /min %AppDataLocal%\GFp0Jak\How-to-buy-bitcoins.html

Download Routine

This Ransomware connects to the following URL(s) to download its component file(s):

  • https://{BLOCKED}s.org/download/release/latest-v8.x/win-x86/node.exe

Other Details

This Ransomware does the following:

  • By default, encrypts all drives present in the system, except for “C:” drives which only encrypts the files inside the following file paths:
    • %Desktop%
    • %User Profile%\Documents
    • %User Profile%\Downloads
    • %User Profile%\Contacts
    • %User Profile%\Pictures
    • %User Profile%\Music
    • %User Profile%\Videos
    • %AppDataLocal%\Microsoft\Outlook

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Ransomware Routine

This Ransomware appends the following extension to the file name of the encrypted files:

  • .encrypted

It drops the following file(s) as ransom note:

  • %Desktop%\Decrypt-your-files.bat
  • %AppDataLocal%\GFp0JAk\How-to-buy-bitcoins.html
  • %Desktop%\How-to-buy-bitcoins.html

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.410.01
FIRST VSAPI PATTERN DATE: 27 Apr 2023
VSAPI OPR PATTERN File: 18.411.00
VSAPI OPR PATTERN Date: 28 Apr 2023

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    Downloader.VBS.TRX.XXVBS82EFF037

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 4

Restart in Safe Mode

[ Learn More ]

Step 5

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
    • Microsoft Office= %AppDataLocal%\GFp0Jak\GFp0Jak.vbs
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Startup= %AppDataLocal%\GFp0Jak\GFp0Jak.exe%AppDataLocal%\GFp0Jak\lLT8PCI.js decryptStatic
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Windows= cmd /c start /min %AppDataLocal%\GFp0Jak\How-to-buy-bitcoins.html

Step 6

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.
  • %Desktop%\Decrypt-your-files.bat
  • %AppDataLocal%\GFp0JAk\How-to-buy-bitcoins.html
  • %Desktop%\How-to-buy-bitcoins.html
  • %AppDataLocal%\GFp0JAk\GFp0JAk.vbs
  • %AppDataLocal%\GFp0JAk\GFp0JAk.exe
  • %AppDataLocal%\GFp0JAk\lLT8PCI.js
  • %AppDataLocal%\GFp0JAk\{6 Random Characters}.key
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\fs.js
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\package.json
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\graceful-fs.js
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\legacy-streams.js
  • %AppDataLocal%\GFp0JAk\node_modules\graceful-fs\polyfills.js

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.JS.NODERA.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.

Step 8

Restore encrypted files from backup.


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