RANSOM_HIDDENTEARAPT.B

 Analysis by: Jeanne Jocson

 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.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

44,032 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

06 Oct 2016

Payload:

Encrypts files, renames 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 drops and executes the following files:

  • %Application Data%\delback.bat-used for deleting shadow copies(deletes itself afterwards)

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on 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.)

It creates the following folders:

  • C:\Users\{User Name}\AppData\Roaming\GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}

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
Audio HD Driver = "C:\Users\{User Name}\AppData\Roaming\GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}\denve.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
Audio HD Driver = "C:\Users\{User Name}\AppData\Roaming\GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}\denve.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\ProtectedProc\
Options

It adds the following registry entries:

HKEY_CURRENT_USER\Software\ProtectedProc\
Options
Date = "{day+3}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

Dropping Routine

This Trojan drops the following files:

  • {malware folder}2.exe
  • C:\Users\{User Name}\AppData\Roaming\GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}\denve.exe
  • {folder of encrypted files}\DECRYPT_YOUR_FILES.HTML-serves as ransom note

Other Details

This Trojan encrypts files with the following extensions:

  • .txt
  • .pdf
  • .frm
  • .pix
  • .accdb
  • .mdb
  • .cdr
  • .eps
  • .tif
  • .msg
  • .asmx
  • .rpt
  • .arw
  • .qbo
  • .qbw
  • .sldprt
  • .dwf
  • .doc
  • .adi
  • .adt
  • .docx
  • .altr
  • .xls
  • .xlsx
  • .ppt
  • .pptx
  • .odt
  • .jpg
  • .png
  • .csv
  • .sql
  • sln
  • .php
  • .asp
  • .aspx
  • .html
  • .xml
  • .psd
  • .bat
  • .js
  • .css
  • .sqlite
  • .dwg
  • .jpeg

It renames encrypted files using the following names:

  • {filename of encrypted file}.dll

It deletes the initially executed copy of itself

NOTES:

Leaves the the following ransom note:

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.862.06

FIRST VSAPI PATTERN DATE:

27 Oct 2016

VSAPI OPR PATTERN File:

12.863.00

VSAPI OPR PATTERN Date:

28 Oct 2016

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

Delete this registry key

[ 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\Explorer
    • Advanced

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
    • Audio HD Driver = "C:\Users\{User Name}\AppData\Roaming\GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}\denve.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
    • Audio HD Driver = "C:\Users\{User Name}\AppData\Roaming\GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}\denve.exe"

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • C:\Users\{User Name}\AppData\Roaming\GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}

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.
  • {malware folder}2.exe
  • C:\Users\{User Name}\AppData\Roaming\GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}\denve.exe
  • {folder of encrypted files}\DECRYPT_YOUR_FILES.HTML

Step 7

Scan your computer with your Trend Micro product to delete files detected as RANSOM_HIDDENTEARAPT.B. 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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