RANSOM_HIDDENTEARTRANSOM.C

 Analysis by: Joselyn Canuela

 ALIASES:

HEUR:Trojan.Win32.Generic (Kaspersky), Ransom:MSIL/Ryzerlo.A (Microsoft), Gen:Variant.MSILPerseus.64730 (BitDefender)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet


This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

128,512 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

05 Jan 2017

Payload:

Encrypts files

Arrival Details

This Trojan 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 Trojan adds the following processes:

  • {Malware Path}\WebMatrixWeb.exe

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WindowsServiceEngine = "{Malware path and file name}.exe"

Dropping Routine

This Trojan drops the following files:

  • %Desktop%\DOSYALARINIZA ULAŞMAK İÇİN AÇINIZ.html - 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 Trojan encrypts files with the following extensions:

  • .txt
  • .rar
  • .jpg
  • .pdf
  • .sql
  • .png
  • .accdb
  • .xls
  • .xlsx
  • .doc
  • .docx
  • .ppt
  • .pptx
  • .zip
  • .gz
  • .tar
  • .tib
  • .tmp
  • .frm
  • .dwg
  • .pst
  • .psd
  • .ai
  • .svg
  • .gif
  • .bak
  • .db

It renames encrypted files using the following names:

  • {Original file name and extension}.locked

NOTES:

The ransomware encrypts files in the following location:

  • {Drive Letter}
  • The ransomware displays the following ransom note:

      SOLUTION

    Minimum Scan Engine:

    9.850

    FIRST VSAPI PATTERN FILE:

    13.138.02

    FIRST VSAPI PATTERN DATE:

    05 Jan 2017

    VSAPI OPR PATTERN File:

    13.139.00

    VSAPI OPR PATTERN Date:

    06 Jan 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

    Terminate a malware/grayware process

    [ Learn More ]

    *Note: If the detected process is not displayed in theWindows Task Manager, continue doing the next steps.

       
      • WebMatrixWeb.exe

    Step 4

    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
      • WindowsServiceEngine = "{Malware path and file name}.exe"

    Step 5

    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%\DOSYALARINIZA ULAŞMAK İÇİN AÇINIZ.html - ransom note

    Step 6

    Restore encrypted files from backup.

    Step 7

    Scan your computer with your Trend Micro product to delete files detected as RANSOM_HIDDENTEARTRANSOM.C. 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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