Ransom.MSIL.BLACKHEART.AMT

July 07, 2020
 Analysis by: Clive Fuentebella
 ALIASES:

W32/DelShad.AAU!tr.ransom (FORTINET)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

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 connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible.

It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

81,408 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

06 Jul 2020

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 adds the following processes:

  • netsh.exe advfirewall set allprofiles state off
  • cmd.exe /c vssadmin.exe delete shadows /all /quiet

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
taskhostw = {Malware file path and name}

Information Theft

Upon execution of the affected application, it gathers the following information:

  • Country
  • Internet protocol
  • Operating system
  • CPU model
  • Machine name
  • Hard disk used space
  • Size of memory

Other Details

This Ransomware connects to the following website to send and receive information:

  • http://{BLOCKED}iles.online/api

However, as of this writing, the said sites are inaccessible.

Ransomware Routine

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

  • .[recoryfile@tutanota.com].jwjs

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

  • {Encrypted directory}\info.hta

It leaves text files that serve as ransom notes containing the following text:

  • {Encrypted directory}\ReadMe.txt

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.976.02

FIRST VSAPI PATTERN DATE:

07 Jul 2020

VSAPI OPR PATTERN File:

15.977.00

VSAPI OPR PATTERN Date:

08 Jul 2020

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:

    • Troj.Win32.TRX.XXPE50FFF036

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • taskhostw = {Malware file path and name}

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.
  • {Encrypted directory}\ReadMe.txt
  • {Encrypted directory}\info.hta

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.MSIL.BLACKHEART.AMT. 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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