Ransom.MSIL.EPAR.THABAOAH

 Analysis by: Michael Jhon Ofiaza

 ALIASES:

HEUR:Trojan-Ransom.MSIL.Crypmodadv.gen (Kaspersky) ; Ransom.HiddenTear!g1 (Norton)

 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:

Dropped by other malware, 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.

However, as of this writing, the said sites are inaccessible. It deletes itself after execution.

It encrypts files with specific file extensions.

  TECHNICAL DETAILS

File Size:

13,312 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

01 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 adds the following processes:

  • cmd.exe /C Del /Q /F {Malware Path}\{Malware Name}.exe

Other Details

This Ransomware does the following:

  • Connects to the following URL to send encryption key:
    • https://{BLOCKED}s-court.{BLOCKED}h.me/{KEY}

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

It deletes itself after execution.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .txt
  • .docx
  • .doc
  • .ppt
  • .pptx
  • .sql
  • .js
  • .cpp
  • .c
  • .css
  • .apk
  • .xml
  • .psd
  • .img
  • .jpg
  • .jpeg
  • .png
  • .php
  • .py
  • .pdf
  • .mov
  • .mp4
  • .mp3
  • .dmg
  • .iso
  • .avi
  • .wmv
  • .m4a
  • .zip
  • .7z
  • .rar
  • .json
  • .py

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

  • .rape

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

  • {Encrypted Folder}\i_want_your_dick.html

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.772.03

FIRST VSAPI PATTERN DATE:

25 Jan 2019

VSAPI OPR PATTERN File:

14.773.00

VSAPI OPR PATTERN Date:

26 Jan 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

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 Folder}\i_want_your_dick.html

Step 4

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.EPAR.THABAOAH. 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 5

Restore encrypted files from backup.


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