Ransom_HiddenTearRESTORE.A

 Analysis by: Marvelous Pelin

 ALIASES:

Ransom.HiddenTear(Malwarebytes)

 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 encrypts files with specific file extensions. It encrypts files found in specific folders.

  TECHNICAL DETAILS

File Size:

814,080 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

30 May 2017

Payload:

Encrypts files, Drops 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 System Modifications

This Ransomware adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
092 = {malware path}

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1

(Note: The default value data of the said registry entry is {user preference}.)

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = ""

(Note: The default value data of the said registry entry is {user preference}.)

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .asp
  • .aspx
  • .bat
  • .cmd
  • .csv
  • .dll
  • .doc
  • .docx
  • .html
  • .html
  • .ink
  • .java
  • .jpg
  • .kys
  • .mdb
  • .odt
  • .php
  • .png
  • .ppt
  • .pptx
  • .psd
  • .sln
  • .sql
  • .txt
  • .URL
  • .xls
  • .xlsx
  • .xml

It encrypts files found in the following folders:

  • %User Profile%

(Note: %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 renames encrypted files using the following names:

  • {original filename and extension}.r3store

NOTES:
The ransom note contains the following text:

It displays the following image after execution:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.438.04

FIRST VSAPI PATTERN DATE:

30 May 2017

VSAPI OPR PATTERN File:

13.439.00

VSAPI OPR PATTERN Date:

31 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

Restart in Safe Mode

[ Learn More ]

Step 4

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • From: DisableTaskMgr = 1
      To: DisableTaskMgr = {user preference}
  • In HKEY_CURRENT_USER\Control Panel\Desktop
    • From: Wallpaper = ""
      To: Wallpaper = {user preference}

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • 092 = {malware path}

Step 6

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 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom_HiddenTearRESTORE.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 8

Restore encrypted files from backup.


Did this description help? Tell us how we did.