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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_BKDR_Xzutil_Script_CVE_2024_3094_Mar24_1

Detects make file and script contents used by the backdoored XZ library (xzutil) CVE-2024-3094.

ExploitSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Florian Roth
Date
2024-03-30
Modified
2024-04-24
Score / Quality
80 / 85

What this rule detects

Detects make file and script contents used by the backdoored XZ library (xzutil) CVE-2024-3094.

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

Summary generated from the rule's metadata and condition.

Rule source

bkdr-xzutil-script-cve-2024-3094-mar24-1.yarDetection Rule License 1.1
rule SIGNATURE_BASE_BKDR_Xzutil_Script_CVE_2024_3094_Mar24_1 : CVE_2024_3094
{
	meta:
		description = "Detects make file and script contents used by the backdoored XZ library (xzutil) CVE-2024-3094."
		author = "Florian Roth"
		id = "6b62ffc2-d0a7-5810-97a3-c48f7fac300e"
		date = "2024-03-30"
		modified = "2024-04-24"
		reference = "https://www.openwall.com/lists/oss-security/2024/03/29/4"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/bkdr_xz_util_cve_2024_3094.yar#L2-L17"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "d44d0425769fa2e0b6875e5ca25d45b251bbe98870c6b9bef34f7cea9f84c9c3"
		logic_hash = "8d3f5f078a5c827208e04acb7ac1496f473e1236f92561f94d2a3c8156c68ea6"
		score = 80
		quality = 85
		tags = "CVE-2024-3094"

	strings:
		$x1 = "/bad-3-corrupt_lzma2.xz | tr " ascii
		$x2 = "/tests/files/good-large_compressed.lzma|eval $i|tail -c +31265|" ascii
		$x3 = "eval $zrKcKQ" ascii

	condition:
		1 of them
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$x1text"/bad-3-corrupt_lzma2.xz | tr "ascii
$x2text"/tests/files/good-large_compressed.lzma|eval $i|tail -c +31265|"ascii
$x3text"eval $zrKcKQ"ascii

Condition

1 of them

In plain words (Heuristic)

  • At least 1 patterns in the rule must match.

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References

Sample hashes

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

  • d44d0425769fa2e0b6875e5ca25d45b251bbe98870c6b9bef34f7cea9f84c9c3

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: 6b62ffc2-d0a7-5810-97a3-c48f7fac300e

Tags:CVE_2024_3094