Analysis by: Joshua Paul Ignacio

ALIASES:

Ransom:Win32/Phobos.PB!MTB (MICROSOFT),

 THREAT SUBTYPE:

Fileless

 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

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 drops files as ransom note. It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

File Size: 36,352 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 06 Jan 2021
Payload: Displays message/message boxes, Encrypts files, Terminates processes

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 adds the following processes:

  • vssadmin delete shadows /all /quiet
  • wbadmin delete catalog -quiet
  • wmic shadowcopy delete

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
1 = {Malware Path}\{Malware Filename}.exe

Process Termination

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

  • agntsrvc.exe
  • dbeng50.exe
  • dbsnmp.exe
  • encsvc.exe
  • excel.exe
  • firefoxconfig.exe
  • infopath.exe
  • isqlplussvc.exe
  • msaccess.exe
  • msftesql.exe
  • mspub.exe
  • mydesktopqos.exe
  • mydesktopservice.exe
  • mysqld-nt.exe
  • mysqld-opt.exe
  • mysqld.exe
  • ocautoupds.exe
  • ocomm.exe
  • ocssd.exe
  • onenote.exe
  • oracle.exe
  • outlook.exe
  • powerpnt.exe
  • sqbcoreservice.exe
  • sqlagent.exe
  • sqlbrowser.exe
  • sqlservr.exe
  • sqlwriter.exe
  • steam.exe
  • synctime.exe
  • tbirdconfig.exe
  • thebat.exe
  • thebat64.exe
  • thunderbird.exe
  • visio.exe
  • winword.exe
  • wordpadexe
  • xfssvccon.exe

Ransomware Routine

This Ransomware avoids encrypting files found in the following folders:

  • C:\Windows
  • C:\ProgramData\microsoft\windows\caches
  • C:\Users\All Users\Microsoft\Windows\Caches
  • C:\ProgramData
  • C:\Users

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

  • .[{8 Random Characters}].[{BLOCKED}change@qq.com].fair

It drops the following file(s) as ransom note:

  • {Encrypted Directory}\readme-warning.txt

It avoids encrypting files with the following file extensions:

  • makop
  • CARLOS
  • shootlock
  • shootlock2
  • 1recoesufV8Sv6g
  • 1recocr8M4YJskJ7
  • btc
  • KJHslgjkjdfg
  • origami
  • tomas
  • RAGA
  • zbw
  • fireee
  • XXX
  • element
  • HELP
  • zes
  • lockbit
  • captcha
  • gunga
  • fair
  • exe
  • dll

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.544.02
FIRST VSAPI PATTERN DATE: 17 Feb 2021
VSAPI OPR PATTERN File: 16.545.00
VSAPI OPR PATTERN Date: 18 Feb 2021

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    • Troj.Win32.TRX.XXPE50FFF041

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

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 4

Restart in Safe Mode

[ Learn More ]

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
    • 1 = {Malware Path}\{Malware Filename}.exe

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.
  • {Encrypted Directory}\readme-warning.txt

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.MAKOP.J. 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.


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