Ransom.JS.GANDCRAB.MUVEA

 Analysis by: Earle Maui Earnshaw

 ALIASES:

Trojan:Win32/Zpevdo.B (Microsoft); JS.Downloader (Symantec)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • 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:

1,337,367 bytes

File Type:

JS

Memory Resident:

No

Initial Samples Received Date:

03 Dec 2018

Payload:

Connects to URLs/IPs

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 and executes the following files:

  • %Application Data%\mkltkpfcp.log

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.)

It adds the following processes:

  • powershell.exe -ExecutionPolicy Bypass -Command "IEX (([System.IO.File]::ReadAllText('%Application Data%\mkltkpfcp.log')).Replace('#',''));Start-Sleep -s 1000000;"
  • "%System%\wbem\wmic.exe" shadowcopy delete

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Autostart Technique

This Ransomware adds the following lines or registry entries as part of its routine:

  • HKEY_LOCAL_MACHINE\SOFTWARE\ex_data\data
  • HKEY_LOCAL_MACHINE\SOFTWARE\keys_data\data

Other System Modifications

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

HKEY_LOCAL_MACHINE\SOFTWARE\keys_data\
data
Public = {hex values}

HKEY_LOCAL_MACHINE\SOFTWARE\keys_data\
data
Private = {hex values}

HKEY_LOCAL_MACHINE\SOFTWARE\ex_data\
data
ext = {hex values}

It modifies the following registry keys:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Temp%\pidor.bmp

Other Details

This Ransomware connects to the following possibly malicious URL:

  • http://www.{BLOCKED}rsport.biz
  • http://www.{BLOCKED}nau.biz
  • http://www.{BLOCKED}m.com

Ransomware Routine

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

  • .unceq

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

  • %User Temp%\pidor.bmp

(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.842.02

FIRST VSAPI PATTERN DATE:

28 Feb 2019

VSAPI OPR PATTERN File:

14.843.00

VSAPI OPR PATTERN Date:

01 Mar 2019

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 Ransom.JS.GANDCRAB.MUVEA

[ 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

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.

  • HKEY_LOCAL_MACHINE\SOFTWARE\keys_data\data
  • HKEY_LOCAL_MACHINE\SOFTWARE\ex_data\data

Step 5

Restore this modified 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\Control Panel\Desktop
    • From: Wallpaper = "%User Temp%\\pidor.bmp"
      To: Wallpaper = "{User Preference}"

Step 6

Search and delete these files

[ 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.
  • %Application Data%\mkltkpfcp.log
  • %User Temp%\\pidor.bmp

Step 7

Restore encrypted files from backup.

Step 8

Scan your computer with your Trend Micro product to delete files detected as Ransom.JS.GANDCRAB.MUVEA. 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 the following Trend Micro Support pages for more information:


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