Ransom.Win32.DEATHRANSOM.A

December 05, 2019
 Analysis by: Jay Bradley Nebre
 ALIASES:

a variant of Win32/Filecoder.DeathRansom.A trojan(Norton)

 PLATFORM:

Windows

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

  • 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.

It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

File Size:

18,432 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

29 Nov 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:

  • vssadmin.exe delete shadows /all /quiet

Ransomware Routine

This Ransomware avoids encrypting files found in the following folders:

  • ProgramData
  • $Recycle.Bin
  • Program Files
  • Windows
  • All Users
  • AppData

It appends the following extension to the file name of the encrypted files:

  • .chch

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

  • READ_ME.TXT

It avoids encrypting files with the following file extensions:

  • .yyyyyyyyyyyyyyyyyyyyyyyyyyyyy

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.528.03

FIRST VSAPI PATTERN DATE:

29 Nov 2019

VSAPI OPR PATTERN File:

15.529.00

VSAPI OPR PATTERN Date:

30 Nov 2019

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.XXPE50FFF033

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

Enabling Volume Shadow Service

  1. Run the command prompt (cmd.exe) as administrator.
  2. Enable Volume Shadow Service by typing the following command:
    net start vss

Step 5

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.DEATHRANSOM.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 the following Trend Micro Support pages for more information:

Step 6

Restore encrypted files from backup.


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