YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_HKTL_EXPL_POC_NET_Sharepoint_CVE_2023_29357_Sep23_1

Detects a C# POC to exploit CVE-2023-29357 on Microsoft SharePoint servers

HacktoolSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Kompiliert mit YARA-X

Autor: Florian Roth
Datum: 2023-10-01
Geändert: 2023-12-05
Score / Qualität: 80 / 85

Was diese Regel erkennt

Detects a C# POC to exploit CVE-2023-29357 on Microsoft SharePoint servers

Ziele: Windows-PE.

Sie definiert 8 Muster (8 Text, 0 Hex, 0 Regex).

Zusammenfassung aus den Metadaten und der Bedingung der Regel erzeugt.

Regelquelltext

.yar herunterladen

hktl-expl-poc-net-sharepoint-cve-2023-29357-sep23-1.yarDetection Rule License 1.1

rule SIGNATURE_BASE_HKTL_EXPL_POC_NET_Sharepoint_CVE_2023_29357_Sep23_1 : CVE_2023_29357 FILE
{
	meta:
		description = "Detects a C# POC to exploit CVE-2023-29357 on Microsoft SharePoint servers"
		author = "Florian Roth"
		id = "aa6aeb00-b162-538c-a670-cbff525dd8f1"
		date = "2023-10-01"
		modified = "2023-12-05"
		reference = "https://github.com/LuemmelSec/CVE-2023-29357"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/expl_sharepoint_cve_2023_29357.yar#L37-L62"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "cf621cc9c5074f531df61623b09db68478e94ae6a9a7acc26aa8d9dde79bd30c"
		score = 80
		quality = 85
		tags = "CVE-2023-29357, FILE"

	strings:
		$x1 = "{f22d2de0-606b-4d16-98d5-421f3f1ba8bc}" ascii wide
		$x2 = "{F22D2DE0-606B-4D16-98D5-421F3F1BA8BC}" ascii wide
		$s1 = "Bearer"
		$s2 = "hashedprooftoken"
		$s3 = "/_api/web/"
		$s4 = "X-PROOF_TOKEN"
		$s5 = "00000003-0000-0ff1-ce00-000000000000"
		$s6 = "IsSiteAdmin"

	condition:
		uint16( 0 ) == 0x5a4d and filesize < 800KB and ( 1 of ( $x* ) or all of ( $s* ) )
}

Strings (8 Muster)

Bezeichner	Typ	Wert	Modifikatoren
$x1	Text	"{f22d2de0-606b-4d16-98d5-421f3f1ba8bc}"	ascii wide
$x2	Text	"{F22D2DE0-606B-4D16-98D5-421F3F1BA8BC}"	ascii wide
$s1	Text	"Bearer"
$s2	Text	"hashedprooftoken"
$s3	Text	"/_api/web/"
$s4	Text	"X-PROOF_TOKEN"
$s5	Text	"00000003-0000-0ff1-ce00-000000000000"
$s6	Text	"IsSiteAdmin"

Bedingung

uint16( 0 ) == 0x5a4d and filesize < 800KB and ( 1 of ( $x* ) or all of ( $s* ) )

In Worten (Heuristik)

Die Datei muss mit „MZ“ beginnen — eine Windows-Programmdatei (PE).
Die Datei muss kleiner als 800KB sein (eine günstige Grenze, die große Dateien ausschließt).
Alle Muster aus ( $s* ) müssen treffen.
Mindestens 1 Muster aus ( $x* ) müssen treffen.