Saltar al contenido

YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_SUSP_Screenconnect_Exploitation_Artefacts_Feb24

Detects post exploitation indicators observed by HuntressLabs in relation to the ConnectWise ScreenConnect (versions prior to 23.9.8) vulnerability that allows an Authentication Bypass

Sospechoso / huntingSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compila con YARA-X
Autor
Florian Roth
Fecha
2024-02-23
Modificada
2024-04-24
Puntuación / Calidad
75 / 83

Qué detecta esta regla

Detects post exploitation indicators observed by HuntressLabs in relation to the ConnectWise ScreenConnect (versions prior to 23.9.8) vulnerability that allows an Authentication Bypass

Define 28 patrones (28 de texto, 0 hex, 0 regex).

Resumen generado a partir de los metadatos y la condición de la regla.

Código de la regla

susp-screenconnect-exploitation-artefacts-feb24.yarDetection Rule License 1.1
rule SIGNATURE_BASE_SUSP_Screenconnect_Exploitation_Artefacts_Feb24 : SCRIPT
{
	meta:
		description = "Detects post exploitation indicators observed by HuntressLabs in relation to the ConnectWise ScreenConnect (versions prior to 23.9.8) vulnerability that allows an Authentication Bypass"
		author = "Florian Roth"
		id = "079f4153-8bc7-574f-b6fa-af5536b842ab"
		date = "2024-02-23"
		modified = "2024-04-24"
		reference = "https://www.huntress.com/blog/slashandgrab-screen-connect-post-exploitation-in-the-wild-cve-2024-1709-cve-2024-1708"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/expl_connectwise_screenconnect_vuln_feb24.yar#L62-L103"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "6f0d5f878847da1afb0d7b83e84bd337cfa67c36da2cbb33af712ed4ffad490a"
		score = 75
		quality = 83
		tags = "SCRIPT"

	strings:
		$x01 = "-c foreach ($disk in Get-WmiObject Win32_Logicaldisk){Add-MpPreference -ExclusionPath $disk.deviceid}"
		$x02 = ".msi c:\\mpyutd.msi"
		$x03 = "/MyUserName_$env:UserName"
		$x04 = " -OutFile C:\\Windows\\Help\\"
		$x05 = "/Create /TN \\\\Microsoft\\\\Windows\\\\Wininet\\\\UserCache_"
		$x06 = "$e = $r + \"ssh.exe\""
		$x07 = "Start-Process -f $e -a $args -PassThru -WindowStyle Hidden).Id"
		$x08 = "-R 9595:localhost:3389 -p 443 -N -oStrictHostKeyChecking=no "
		$x09 = "chromeremotedesktophost.msi', $env:ProgramData+"
		$x10 = "9595; iwr -UseBasicParsing "
		$x11 = "curl  https://cmctt.]com/pub/media/wysiwyg/"
		$x12 = ":8080/servicetest2.dll"
		$x13 = "/msappdata.msi c:\\mpyutd.msi"
		$x14 = "/svchost.exe -OutFile "
		$x15 = "curl http://minish.wiki.gd"
		$x16 = " -Headers @{'ngrok-skip-browser-warning'='true'} -OutFile "
		$x17 = "rundll32.exe' -Headers @"
		$x18 = "/nssm.exe' -Headers @"
		$x19 = "c:\\programdata\\update.dat UpdateSystem"
		$x20 = "::size -eq 4){\\\"TVqQAA" ascii wide
		$x21 = "::size -eq 4){\"TVqQAA" ascii wide
		$x22 = "-nop -c [System.Reflection.Assembly]::Load(([WmiClass]'root\\cimv2:System_"
		$xp0 = "/add default test@2021! /domain"
		$xp1 = "/add default1 test@2021! /domain"
		$xp2 = "oldadmin Pass8080!!"
		$xp3 = "temp 123123qwE /add "
		$xp4 = "oldadmin \"Pass8080!!\""
		$xp5 = "nssm set xmrig AppDirectory "

	condition:
		1 of ( $x* )
}

Cadenas (28 patrones)

IdentificadorTipoValorModificadores
$x01texto"-c foreach ($disk in Get-WmiObject Win32_Logicaldisk){Add-MpPreference -ExclusionPath $disk.deviceid}"
$x02texto".msi c:\\mpyutd.msi"
$x03texto"/MyUserName_$env:UserName"
$x04texto" -OutFile C:\\Windows\\Help\\"
$x05texto"/Create /TN \\\\Microsoft\\\\Windows\\\\Wininet\\\\UserCache_"
$x06texto"$e = $r + \"ssh.exe\""
$x07texto"Start-Process -f $e -a $args -PassThru -WindowStyle Hidden).Id"
$x08texto"-R 9595:localhost:3389 -p 443 -N -oStrictHostKeyChecking=no "
$x09texto"chromeremotedesktophost.msi', $env:ProgramData+"
$x10texto"9595; iwr -UseBasicParsing "
$x11texto"curl https://cmctt.]com/pub/media/wysiwyg/"
$x12texto":8080/servicetest2.dll"
$x13texto"/msappdata.msi c:\\mpyutd.msi"
$x14texto"/svchost.exe -OutFile "
$x15texto"curl http://minish.wiki.gd"
$x16texto" -Headers @{'ngrok-skip-browser-warning'='true'} -OutFile "
$x17texto"rundll32.exe' -Headers @"
$x18texto"/nssm.exe' -Headers @"
$x19texto"c:\\programdata\\update.dat UpdateSystem"
$x20texto"::size -eq 4){\\\"TVqQAA"ascii wide
$x21texto"::size -eq 4){\"TVqQAA"ascii wide
$x22texto"-nop -c [System.Reflection.Assembly]::Load(([WmiClass]'root\\cimv2:System_"
$xp0texto"/add default test@2021! /domain"
$xp1texto"/add default1 test@2021! /domain"
$xp2texto"oldadmin Pass8080!!"
$xp3texto"temp 123123qwE /add "
$xp4texto"oldadmin \"Pass8080!!\""
$xp5texto"nssm set xmrig AppDirectory "

Condición

1 of ( $x* )

En palabras sencillas (Heurística)

  • Deben coincidir al menos 1 patrones de ( $x* ).

Prueba esta regla en tu navegador

Arrastra un archivo para escanearlo con esta regla usando YARA-X compilado a WebAssembly. No se sube nada.

Arrastra un archivo aquí o haz clic para elegirSe escanea en local con YARA-X. Archivos de hasta 200 MB.

Abrir en el editor

Referencias

Licencia y atribución

Autor: Florian Roth

Repositorio de origen: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

Licencia: Detection Rule License 1.1 (licencia del repositorio)

Regla original

Obtenida a través de YARA Forge 20260927, que añade a los nombres el prefijo de la fuente y campos meta normalizados.

Id de la regla: 079f4153-8bc7-574f-b6fa-af5536b842ab

Etiquetas:SCRIPT