RANSOM_HIDDENTEAR.CRYPKILS

December 05, 2017
 Analysis by: Rheniel Rhay Ramos
 ALIASES:

Ransom.Gendarmerie (Malwarebytes); Ransom:MSIL/Ryzerlo.A (Microsoft); Ransom.HiddenTear!g1 (Symantec)

 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:

Downloaded from the Internet, Dropped by other malware

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. It encrypts files found in specific folders. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

193,024 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

30 Oct 2017

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.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .txt
  • .doc
  • .docx
  • .xls
  • .index
  • .pdf
  • .zip
  • .rar
  • .css
  • .lnk
  • .xlsx
  • .ppt
  • .pptx
  • .odt
  • .jpg
  • .bmp
  • .png
  • .csv
  • .sql
  • .mdb
  • .sln
  • .php
  • .asp
  • .aspx
  • .html
  • .xml
  • .psd
  • .bk
  • .bat
  • .mp3
  • .mp4
  • .wav
  • .wma
  • .avi
  • .divx
  • .mkv
  • .mpeg
  • .wmv
  • .mov
  • .ogg
  • .exe
  • .JPEG
  • .TXT
  • .JPG

It encrypts files found in the following folders:

  • %Desktop%
  • %User Profile%\Downloads
  • %User Profile%\Documents
  • %User Profile%\Pictures
  • %User Profile%\Music
  • %User Profile%\Videos

(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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

  • .hacking

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

  • {Folder containing Encrypted Files}\Message_Important.txt

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

  • instruction à faire pour récupérer la clé de décryptage de vos fichiers crypter

    email de contact : {BLOCKED}bercrimedivision@hotmail.com

    1) acheter des coupons neosurf de 100€ ,euros .

    2) vous pouvez acheter les coupons neosurf ici https://www.recharge.fr/carte-neosurf

    3) vous pouvez aussi acheter les coupons neosurf ici https://www.neosurf.com/fr_FR ou dans les bureaux de tabac

    4) dès que je reçois les coupons neosurf ,je vous envoie la clé de décryptage par email.

    Contact Email : {BLOCKED}bercrimedivision@hotmail.com

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.788.04

FIRST VSAPI PATTERN DATE:

30 Oct 2017

VSAPI OPR PATTERN File:

13.789.00

VSAPI OPR PATTERN Date:

31 Oct 2017

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.  
  • {Folder containing Encrypted Files}\Message_Important.txt

Step 4

Scan your computer with your Trend Micro product to delete files detected as RANSOM_HIDDENTEAR.CRYPKILS. 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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