Analysis by: Ryan Paolo Maglaque
ALIASES:

Ransom.HiddenTear!g1(Norton);Troj/Cryptear-A

 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.

It connects to certain websites to send and receive information.

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

  TECHNICAL DETAILS

File Size: 437,680 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 26 May 2017
Payload: Connects to URLs/IPs, 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.

Other Details

This Ransomware connects to the following website to send and receive information:

  • http://{BLOCKED}.{BLOCKED}.116.181/write.php?info={Computer Name}-{User Name}%20password%20=%20{key}

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .txt
  • .exe
  • .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
  • .dll
  • .bin
  • .conf
  • .log

It encrypts files found in the following folders:

  • C:\Users\{User name}\Desktop
  • C:\Users\{User name}\Downloads
  • C:\Users\{User name}\Documents
  • C:\Users\{User name}\Pictures
  • C:\Users\{User name}\Music
  • C:\Users\{User name}\Videos

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

  • .kys

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

  • C:\Users\{User name}\Desktop\Read Me.txt

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

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.430.05
FIRST VSAPI PATTERN DATE: 26 May 2017
VSAPI OPR PATTERN File: 13.431.00
VSAPI OPR PATTERN Date: 27 May 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.  
  • C:\Users\{User name}\Desktop\Read Me.txt

Step 4

Scan your computer with your Trend Micro product to delete files detected as RANSOM_HIDDENTEARKYS.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 this Knowledge Base page for more information.

Step 5

Restore encrypted files from backup.


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