Analysis by: Ryan Paolo Maglaque
ALIASES:

Ransom:Win32/HiddenTear.gen(Microsoft); Ransom.HiddenTear(Malwarebytes); Trojan-Ransom.HiddenTear(Emsisoft); TR/HiddenTear.feetj(Avira)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: ransomware

  • Destructiveness: No

  • Encrypted: Yes

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

  TECHNICAL DETAILS

File Size: 1,194,046 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 17 Mar 2017
Payload: Connects to URLs/IPs, 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:

  • %Desktop%\READ_IT.txt ← Ransom Note

(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.)

Other Details

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

  • http://www.titanhdri.{BLOCKED}b.com:443

It encrypts files with the following extensions:

  • .txt
  • .doc
  • .docx
  • .xls
  • .xlsx
  • .ppt
  • .pptx
  • .odt
  • .jpg
  • .png
  • .csv
  • .sql
  • .mdb
  • .sln
  • .php
  • .asp
  • .aspx
  • .html
  • .xml
  • .psd

It renames encrypted files using the following names:

  • {Original File Name}.locked

It does the following:

  • Executes the following command: cmd.exe /c net stop Spooler

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

NOTES:

There's also a possible error in code of malware

Content of Ransom Note:

  • Send an email at {BLOCKED}ChessDecrypt@macr2.com on how to decrypt your files

    •   SOLUTION

    Minimum Scan Engine: 9.850
    FIRST VSAPI PATTERN FILE: 13.284.02
    FIRST VSAPI PATTERN DATE: 18 Mar 2017
    VSAPI OPR PATTERN File: 13.285.00
    VSAPI OPR PATTERN Date: 19 Mar 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

    Restart in Safe Mode

    [ Learn More ]

    Step 4

    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.  
    • %Desktop%\READ_IT.txt

    Step 5

    Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_HIDDENTEARMNC.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.


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