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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_EXPL_Cleo_Exploitation_Log_Indicators_Dec24

Detects indicators found in logs during and after Cleo software exploitation (as reported by Huntress in December 2024)

ExploitSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Florian Roth
Date
2024-12-10
Modified
2024-12-12
Score / Quality
75 / 85

What this rule detects

Detects indicators found in logs during and after Cleo software exploitation (as reported by Huntress in December 2024)

It defines 3 patterns (3 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

expl-cleo-exploitation-log-indicators-dec24.yarDetection Rule License 1.1
rule SIGNATURE_BASE_EXPL_Cleo_Exploitation_Log_Indicators_Dec24 : SCRIPT
{
	meta:
		description = "Detects indicators found in logs during and after Cleo software exploitation (as reported by Huntress in December 2024)"
		author = "Florian Roth"
		id = "385042a9-fc8c-5b50-975f-3436a16e6861"
		date = "2024-12-10"
		modified = "2024-12-12"
		reference = "https://www.huntress.com/blog/threat-advisory-oh-no-cleo-cleo-software-actively-being-exploited-in-the-wild"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/expl_cleo_dec24.yar#L2-L16"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "a7e6713a08d7cce00cffba8daa12b251ccc12dc8d5a5f38d568bd5054e3783a2"
		score = 75
		quality = 85
		tags = "SCRIPT"

	strings:
		$x1 = "Note: Processing autorun file 'autorun\\health" ascii wide
		$x2 = "60282967-dc91-40ef-a34c-38e992509c2c.xml" ascii wide
		$x3 = "<Detail level=\"1\">Executing 'cmd.exe /c \"powershell -NonInteractive -EncodedCommand " ascii wide

	condition:
		1 of them
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$x1text"Note: Processing autorun file 'autorun\\health"ascii wide
$x2text"60282967-dc91-40ef-a34c-38e992509c2c.xml"ascii wide
$x3text"<Detail level=\"1\">Executing 'cmd.exe /c \"powershell -NonInteractive -EncodedCommand "ascii wide

Condition

1 of them

In plain words (Heuristic)

  • At least 1 patterns in the rule must match.

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References

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: 385042a9-fc8c-5b50-975f-3436a16e6861

Tags:SCRIPT