YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_APT_EXPL_Sharepoint_CVE_2025_53770_Forensicartefact_Jul25_2

Detects URIs accessed during the exploitation of SharePoint RCE vulnerability CVE-2025-53770

APT / threat actorSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X

Author: Florian Roth
Date: 2025-07-20
Modified: 2025-07-24
Score / Quality: 70 / 85

What this rule detects

Detects URIs accessed during the exploitation of SharePoint RCE vulnerability CVE-2025-53770

It defines 11 patterns (11 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

apt-expl-sharepoint-cve-2025-53770-forensicartefact-jul25-2.yarDetection Rule License 1.1

rule SIGNATURE_BASE_APT_EXPL_Sharepoint_CVE_2025_53770_Forensicartefact_Jul25_2 : CVE_2025_53770
{
	meta:
		description = "Detects URIs accessed during the exploitation of SharePoint RCE vulnerability CVE-2025-53770"
		author = "Florian Roth"
		id = "c6f26461-04b8-5d69-bf28-e47411c38c82"
		date = "2025-07-20"
		modified = "2025-07-24"
		reference = "https://research.eye.security/sharepoint-under-siege/"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/expl_sharepoint_jul25.yar#L76-L106"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "30955794792a7ce045660bb1e1917eef36f1d5865891b8110bf982382b305b27"
		hash = "b336f936be13b3d01a8544ea3906193608022b40c28dd8f1f281e361c9b64e93"
		logic_hash = "5ae0620e7e1c1908ad54ac4e41c53240f738631c20577fd65fb29008945347a8"
		score = 70
		quality = 85
		tags = "CVE-2025-53770"

	strings:
		$x1 = "-EncodedCommand JABiAGEAcwBlADYANABTAHQAcgBpAG4AZwAgAD0" ascii wide
		$x2 = "TEMPLATE\\LAYOUTS\\spinstall" ascii wide
		$x3 = "TEMPLATE\\LAYOUTS\\ghostfile" ascii wide
		$x4 = "TEMPLATE\\LAYOUTS\\1.css" ascii wide
		$x5 = "Mozilla/5.0+(Windows+NT+10.0;+Win64;+x64;+rv:120.0)+Gecko/20100101+Firefox/120.0 /_layouts/SignOut.aspx" ascii wide
		$xe1 = "TQBJAEMAUgBPAFMAfgAxAFwAVwBFAEIAUwBFAFIAfgAxAFwAMQA2AFwAVABFAE0AUABMAEEAVABFAFwATABBAFkATwBVAFQAUwBcA"
		$xe2 = "0ASQBDAFIATwBTAH4AMQBcAFcARQBCAFMARQBSAH4AMQBcADEANgBcAFQARQBNAFAATABBAFQARQBcAEwAQQBZAE8AVQBUAFMAXA"
		$xe3 = "NAEkAQwBSAE8AUwB+ADEAXABXAEUAQgBTAEUAUgB+ADEAXAAxADYAXABUAEUATQBQAEwAQQBUAEUAXABMAEEAWQBPAFUAVABTAFwA"
		$xe4 = "TQBJAEMAUgBPAFMAfgAxAFwAVwBFAEIAUwBFAFIAfgAxAFwAMQA1AFwAVABFAE0AUABMAEEAVABFAFwATABBAFkATwBVAFQAUwBcA"
		$xe5 = "0ASQBDAFIATwBTAH4AMQBcAFcARQBCAFMARQBSAH4AMQBcADEANQBcAFQARQBNAFAATABBAFQARQBcAEwAQQBZAE8AVQBUAFMAXA"
		$xe6 = "NAEkAQwBSAE8AUwB+ADEAXABXAEUAQgBTAEUAUgB+ADEAXAAxADUAXABUAEUATQBQAEwAQQBUAEUAXABMAEEAWQBPAFUAVABTAFwA"

	condition:
		1 of them
}

Strings (11 patterns)

Identifier	Type	Value	Modifiers
$x1	text	"-EncodedCommand JABiAGEAcwBlADYANABTAHQAcgBpAG4AZwAgAD0"	ascii wide
$x2	text	"TEMPLATE\\LAYOUTS\\spinstall"	ascii wide
$x3	text	"TEMPLATE\\LAYOUTS\\ghostfile"	ascii wide
$x4	text	"TEMPLATE\\LAYOUTS\\1.css"	ascii wide
$x5	text	"Mozilla/5.0+(Windows+NT+10.0;+Win64;+x64;+rv:120.0)+Gecko/20100101+Firefox/120.0 /_layouts/SignOut.aspx"	ascii wide
$xe1	text	"TQBJAEMAUgBPAFMAfgAxAFwAVwBFAEIAUwBFAFIAfgAxAFwAMQA2AFwAVABFAE0AUABMAEEAVABFAFwATABBAFkATwBVAFQAUwBcA"
$xe2	text	"0ASQBDAFIATwBTAH4AMQBcAFcARQBCAFMARQBSAH4AMQBcADEANgBcAFQARQBNAFAATABBAFQARQBcAEwAQQBZAE8AVQBUAFMAXA"
$xe3	text	"NAEkAQwBSAE8AUwB+ADEAXABXAEUAQgBTAEUAUgB+ADEAXAAxADYAXABUAEUATQBQAEwAQQBUAEUAXABMAEEAWQBPAFUAVABTAFwA"
$xe4	text	"TQBJAEMAUgBPAFMAfgAxAFwAVwBFAEIAUwBFAFIAfgAxAFwAMQA1AFwAVABFAE0AUABMAEEAVABFAFwATABBAFkATwBVAFQAUwBcA"
$xe5	text	"0ASQBDAFIATwBTAH4AMQBcAFcARQBCAFMARQBSAH4AMQBcADEANQBcAFQARQBNAFAATABBAFQARQBcAEwAQQBZAE8AVQBUAFMAXA"
$xe6	text	"NAEkAQwBSAE8AUwB+ADEAXABXAEUAQgBTAEUAUgB+ADEAXAAxADUAXABUAEUATQBQAEwAQQBUAEUAXABMAEEAWQBPAFUAVABTAFwA"

Condition

1 of them

In plain words (Heuristic)

At least 1 patterns in the rule must match.

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References

https://research.eye.security/sharepoint-under-siege/

Sample hashes

Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).

30955794792a7ce045660bb1e1917eef36f1d5865891b8110bf982382b305b27
b336f936be13b3d01a8544ea3906193608022b40c28dd8f1f281e361c9b64e93

Licence & attribution

Author: Florian Roth

Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

Licence: Detection Rule License 1.1 (repository licence)

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: c6f26461-04b8-5d69-bf28-e47411c38c82

Tags:CVE_2025_53770

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