Analysis by: Bryelle Timothy Nisperos

ALIASES:

MSIL/Filecoder.DP!tr.ransom (FORTINET), Ransom:MSIL/FileCoder!MTB (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Canal de infección Downloaded from the Internet

This Ransomware may be unknowingly downloaded by a user while visiting malicious websites.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

It encrypts files found in specific folders.

  TECHNICAL DETAILS

Tamaño del archivo 16,712,287 bytes
Tipo de archivo EXE
Residente en memoria Yes
Fecha de recepción de las muestras iniciales 27 Mar 2023
Carga útil Drops files, Modifies system registry, Terminates processes, Restarts system, Encrypts files

Arrival Details

This Ransomware may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This Ransomware drops and executes the following files:

  • MBRiCoreX.exe

It adds the following processes:

  • %System%\vssadmin.exe vssadmin delete shadows /all /quiet
  • %System%\NetSh.exe NetSh Advfirewall set allprofiles state off
  • %System%\Shutdown.exe -r -t 00 -f

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
UpdateBackUp = {Malware Path}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
UpdateBackUp = {Malware Path}

HKEY_LOCAL_MACHINE\Software\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Run
UpdateBackUp = {Malware Path}

Other System Modifications

This Ransomware modifies the following registry entries:

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Windows Defender
DisableAntiSpyware = 1

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Windows Defender
DisableRoutinelyTakingAction = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
WindowsDefenderMAJ = 1

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
WindowsDefenderMAJ = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows Script Host\Settings
Enabled = 0

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows Script Host\Settings
Enabled = 0

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows NT\SystemRestore
DisableSR = 1

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Windows NT\SystemRestore
DisableSR = 1

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows NT\SystemRestore
DisableConfig = 1

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Windows NT\SystemRestore
DisableConfig = 1

HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services
USBSTOR = 4

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services
USBSTOR = 4

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

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

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Windows
DisableCMD = 2

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Windows\System
DisableCMD = 2

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft
DisableCMD = 2

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows
DisableCMD = 2

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows\System
DisableCMD = 2

HKEY_CURRENT_USER\Software\Policies\
Microsoft
DisableCMD = 2

HKEY_CURRENT_USER\Software\Policies\
Microsoft\MMC\{8FC0B734-A0E1-11D1-A7D3-0000F87571E3}
Restrict_Run = 1

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\MMC\{8FC0B734-A0E1-11D1-A7D3-0000F87571E3}
Restrict_Run = 1

HKEY_CURRENT_USER\SOFTWARE\Policies\
Microsoft\Windows Defender\Real-Time Protection
DisableRealtimeMonitoring = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows Defender\Real-Time Protection
DisableRealtimeMonitoring = 1

HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services
SecurityHealthService = 4

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services
SecurityHealthService = 4

HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services
WdNisSvc = 3

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services
WdNisSvc = 3

HKEY_CURRENT_USER\SYSTEM\CurrentControlSet\
Services
WinDefend = 3

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services
WinDefend = 3

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = 0

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoControlPanel = 1

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Control\SafeBoot\Minimal
MinimalX = 1

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoRun = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoRun = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = {Malware Path}\{Malware Filename}.exe

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = 1

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

Propagation

This Ransomware drops the following copy(ies) of itself in all removable drives:

  • {Removable Drive}:\Copter.flv.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[autorun]
open=Copter.flv.exe
shellexecute=Copter.flv.exe

Process Termination

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

  • ProcessHacker
  • procexp64
  • msconfig
  • taskmgr
  • chrome
  • firefox
  • regedit
  • opera
  • UserAccountControlSettings
  • yandex
  • microsoftedge
  • microsoftedgecp
  • iexplore

Other Details

This Ransomware does the following:

  • It disables the following:
    • Windows Defender
    • System Restore
    • Task Manager
    • CMD
    • Run Command
    • Control Panel
    • Safe Boot
    • Registry Tools
    • Windows Script Host
    • USB driver

    It disables executing the following applications by adding the following registry entries:
    • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\{application}
      • Debugger = RIP

    where {application} are as follows:
    • msconfig.exe
    • taskmgr.exe
    • cmd.exe
    • chrome.exe
    • firefox.exe
    • opera.exe
    • microsoftedge.exe
    • microsoftedgecp.exe
    • notepad++.exe
    • iexplore.exe
    • notepad.exe
    • MSASCuiL.exe
    • mmc.exe
    • gpedit.msc
    • UserAccountControlSettings.exe
    • Autoruns64.exe
    • Autoruns.exe
    • systemexplorer.exe
    • taskkill.exe
    • powershell.exe
    • yandex.exe
    • attrib.exe
    • bcdedit.exe
    • sethc.exe
    • mspaint.exe
    • dllhost.exe
    • rundll.exe
    • rundll32.exe
    • cabinet.dll
    • chkdsk.exe
    • DBGHELP.exe
    • DCIMAN32.exe
    • wmplayer.exe
    • ksuser.dll
    • mpg4dmod.dll
    • mydocs.dll
    • rasman.dll
    • shellstyle.dll
    • secpol.msc
    • url.dll
    • usbui.dll
    • webcheck.dll
    • recoverydrive.exe
    • logoff.exe
    • control.exe
    • explorer.exe
    • regedit.exe
    • csrss.exe

    It also connects to http://{BLOCKED}somatic.com/

Ransomware Routine

This Ransomware encrypts files found in the following folders:

  • %User Profile%\Downloads
  • %User Profile%\Desktop
  • D:\

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

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

  • .ANNABELLE

NOTES:
This ransomware displays the following message box:

It then reboots the system and displays this lock screen:

Once the user clicks the button “Credit”, it displays the following:


Once the user clicks the button “Information”, it displays the following:


Once the user clicks the button “Encrypted Files”, it displays the following:

Once the user clicks the button “Check Payment / Get Code”, it displays the following:

The unlock key is: wHYecVx64uX2zjVedeTeyRLN
It displays the following window that shows the decryption process of the malware:

It reboots the system and displays the malware's MBR, making the system unbootable:

  SOLUTION

Motor de exploración mínimo 9.800
Primer archivo de patrones de VSAPI 18.323.00
Primera fecha de publicación de patrones de VSAPI 17 Mar 2023
Versión de patrones OPR de VSAPI 18.323.00
Fecha de publicación de patrones OPR de VSAPI 17 Mar 2023

NOTES:
Restore the system from backup or reinstall the operating system (OS). The system may be made bootable by doing a system repair using a Windows installer disk.


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