Analysis by: Earle Maui Earnshaw
ALIASES:

Trojan:Win32/Occamy.C (Microsoft); Trojan-Ransom.ShellLocker (Ikarus)

 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: Downloaded from the Internet, Dropped by other malware

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 found in specific folders.

  TECHNICAL DETAILS

File Size: 111,616 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 18 Dec 2018
Payload: Terminates processes, 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.

Installation

This Ransomware drops the following files:

  • %AppDataLocal%\TempTqykUo3.png

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista, 7, and 8.)

It drops the following copies of itself into the affected system:

  • %User Startup%\svchost.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows XP, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Other System Modifications

This Ransomware modifies the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = C:\Users\dyituser_732\AppData\Local\TempTqykUo3.png

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = C:\Users\DYITUS~1\AppData\Local\Temp\BGInfo.bmp

Process Termination

This Ransomware terminates the following processes if found running in the affected system's memory:

  • TaskManager
  • cmd
  • procexp
  • procexp64x
  • regedit
  • CCleaner64
  • msconfig

Other Details

This Ransomware does the following:

  • Encrypts the following drive letters:
    • Drive Letters A to Y
  • Downloads a file from the following URL links:
    • http://i.{BLOCKED}r.com/TqykUo3.png
  • Disables the following Key Strokes:
    • Ctrl +Esc
    • Alt + Tab
    • Alt + Esc
  • It displays the Ransom Note asking the victim to subscribe by following the link : https://www.youtube.com/channel/UC-lHJZR3Gqxm24_Vd_AJ5Yw?sub_confirmation=1

Ransomware Routine

This Ransomware encrypts files found in the following folders:

  • %User Profile%\Desktop
  • %User Profile%\MyMusic
  • %User Profile%\Personal
  • %User Profile%\MyVideos
  • %User Profile%\Contacts
  • %User Profile%\Downloads
  • %User Profile%\OneDrive

(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, 7, and 8.)

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

  • {File Name}.PewDiePie

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.696.04
FIRST VSAPI PATTERN DATE: 18 Dec 2018
VSAPI OPR PATTERN File: 14.697.00
VSAPI OPR PATTERN Date: 19 Dec 2018

Step 1

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 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

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\Control Panel\Desktop
    • Wallpaper = "{User Preference}"

Step 5

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.  
  • %AppDataLocal%\TempTqykUo3.png
  • %User Startup%\svchost.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.MSIL.PEWDIEPIE.THABAHAH. 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 7

Restore encrypted files from backup.


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