Ransom.MSIL.BEARCRYPT.A

May 01, 2020
 Analysis by: Patrick Noel Collado
 ALIASES:

Ransom:MSIL/BearCrypt!MSR (Microsoft), MSIL/Filecoder.ZE trojan (NOD32)

 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

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 encrypts files with specific file extensions.

  TECHNICAL DETAILS

File Size:

8,704 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

12 Apr 2020

Payload:

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 drops the following files:

  • If an html file was encrypted:
    • {Malware Directory}\.html
  • If an png file was encrypted:
    • {Malware Directory}\.png
  • If an jpg file was encrypted:
    • {Malware Directory}\.jpg
  • If an iso file was encrypted:
    • {Malware Directory}\.iso
  • {Directory where a file was encrypted}\ReadMe.txt -> Contains encrypted key used for encryption

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .jpg
  • .html
  • .iso
  • .png

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

  • .crypt

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.802.02

FIRST VSAPI PATTERN DATE:

13 Apr 2020

VSAPI OPR PATTERN File:

15.803.00

VSAPI OPR PATTERN Date:

14 Apr 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.XXPE50FFF034

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

Identify and terminate files detected as Ransom.MSIL.BEARCRYPT.A

[ 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 5

Search and delete this file

[ 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.
  • {Malware Directory}\.html
  • {Malware Directory}\.png
  • {Malware Directory}\.jpg
  • {Malware Directory}\.iso
  • {Malware Directory}\{Malware Name}.exe
  • {Directory where a file was encrypted}\ReadMe.txt

Step 6

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.BEARCRYPT.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:


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