Analysis by: Carl Jayson Peliña
ALIASES:

Gen:Variant.Ransom.Cerber.644 (BITDEFENDER)

 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 does not have any propagation routine.

It does not have any backdoor routine.

It does not have any information-stealing capability.

It drops files as ransom note. It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

File Size: 5,347,840 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 08 Dec 2020
Payload: 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:

  • wmic.exe shadowcopy delete
  • bcdedit /set {default} recoveryenabled No
  • bcdedit /set {default} bootstatuspolicy IgnoreAllFailures
  • bcdedit /set {globalsettings} advanceoptions false

Propagation

This Ransomware does not have any propagation routine.

Backdoor Routine

This Ransomware does not have any backdoor routine.

Information Theft

This Ransomware does not have any information-stealing capability.

Other Details

This Ransomware does the following:

  • Checks computer's language and terminate itself if any of the following language is detected:
    • Azerbaijani
    • Armenian
    • Belorussian
    • Kazakh
    • Kyrgyz
    • Moldavian
    • Tajik
    • Russian
    • Turkmen
    • Uzbek
    • Ukrainian
    • Georgian
  • It requires a specific argument to proceed with its encryption routine.

It accepts the following parameters:

  • -vmback -> deletes shadow copies and encrypts the whole machine avoiding files and file extensions stated below
  • -force {Path} -> deletes shadow copies and encrypts only the path provided
  • -list {Text File} -> deletes shadow copies and encrypts only the directories indicated on the text file
  • -backup -> delete shadows copies only
  • -pass {key} -> decryption of some portion of the malware.

Ransomware Routine

This Ransomware avoids encrypting files with the following strings in their file name:

  • autorun.inf
  • boot.ini
  • bootfont.bin
  • bootsect.bak
  • bootmgr
  • bootmgr.efi
  • bootmgfw.efi
  • desktop.ini
  • iconcache.db
  • ntldr
  • ntuser.dat
  • ntuser.dat.log
  • ntuser.ini
  • thumbs.db

It avoids encrypting files found in the following folders:

  • Windows
  • Windos.old
  • Tor browser
  • Internet Explorer
  • Google
  • Opera
  • Opera Software
  • Mozilla
  • Mozilla Firefox
  • $Recycle.Bin
  • ProgramData
  • All Users

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

  • $_R_A_G_N_A_R_{8 Characters based on Computer Name}_$.txt

It avoids encrypting files with the following file extensions:

  • .sys
  • .dll
  • .lnk
  • .msi
  • .drv
  • .exe
  • .log

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.400.05
FIRST VSAPI PATTERN DATE: 08 Dec 2020
VSAPI OPR PATTERN File: 16.401.00
VSAPI OPR PATTERN Date: 09 Dec 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.XXPE50FFF038

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.Win32.RAGNAR.FAIL

[ 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 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.
  • $_R_A_G_N_A_R_{8 Characters based on Computer Name}_$.txt

Step 6

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.RAGNAR.FAIL. 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 7

Restore encrypted files from backup.


Did this description help? Tell us how we did.