ALIASES:

JS/Drop-BMO (Sophos)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size: 29,637 bytes
File Type: JS
Memory Resident: Yes
Initial Samples Received Date: 21 Oct 2019

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 adds the following processes:

  • "regedit.exe" "%User Temp%\ebgeaegdbdecaedfebace.reg"
  • %User Temp%\ebgeaegdbdecaedfebace.reg

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
8337ecf2e08c721ff4ba7dbed7d63814d4db8d2a = "wscript.exe //b {malware path and file name}.js"

It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %user startup%\{malware file name}.js

Other System Modifications

This Ransomware adds the following registry keys:

HKEY_LOCAL_MACHINE\software\8337ecf2e08c721ff4ba7dbed7d63814d4db8d2a

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows Defender

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
8337ecf2e08c721ff4ba7dbed7d63814d4db8d2a
(Default) = "false - 23/6/2019"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Run
8337ecf2e08c721ff4ba7dbed7d63814d4db8d2a = "wscript.exe //b {malware path and file name}.js"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows Defender
DisableAntiSpyware = "1"

Dropping Routine

This Ransomware drops the following files:

  • F:\mail_client.lnk
  • F:\data.lnk
  • F:\wlines.lnk
  • %User Temp%\ebgeaegdbdecaedfebace.reg
  • f:\{malware file name}.js

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other Details

This Ransomware connects to the following possibly malicious URL:

  • {BLOCKED}8.152.217

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.850

Step 1

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 2

Restart in Safe Mode

[ Learn More ]

Step 3

Identify and terminate files detected as Ransom.JS.GANDCRAB.MUVED

[ 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 key

[ 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_LOCAL_MACHINE\software
    • 8337ecf2e08c721ff4ba7dbed7d63814d4db8d2a
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft
    • Windows Defender

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
    • 8337ecf2e08c721ff4ba7dbed7d63814d4db8d2a = "wscript.exe //b {malware path and file name}.js"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\8337ecf2e08c721ff4ba7dbed7d63814d4db8d2a
    • (Default) = "false - 23/6/2019"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run
    • 8337ecf2e08c721ff4ba7dbed7d63814d4db8d2a = "wscript.exe //b {malware path and file name}.js"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
    • DisableAntiSpyware = "1"

Step 6

Search and delete these components

[ Learn More ]
There may be some components 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.
  • F:\mail_client.lnk
  • F:\data.lnk
  • F:\wlines.lnk
  • %User Temp%\ebgeaegdbdecaedfebace.reg
  • f:\{malware file name}.js

Step 7

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