YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_APT_MAL_LUA_Hunting_Lua_SEASPRAY_1

Hunting rule looking for strings observed in SEASPRAY samples.

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

Author: Mandiant
Date: 2023-06-15
Modified: 2023-12-05
Score / Quality: 70 / 85

What this rule detects

Hunting rule looking for strings observed in SEASPRAY samples.

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

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

apt-mal-lua-hunting-lua-seaspray-1.yarDetection Rule License 1.1

rule SIGNATURE_BASE_APT_MAL_LUA_Hunting_Lua_SEASPRAY_1
{
	meta:
		description = "Hunting rule looking for strings observed in SEASPRAY samples."
		author = "Mandiant"
		id = "8c744b85-b61e-56d0-8a9e-ae6a954e1b95"
		date = "2023-06-15"
		modified = "2023-12-05"
		reference = "https://www.mandiant.com/resources/blog/barracuda-esg-exploited-globally"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_barracuda_esg_unc4841_jun23.yar#L213-L228"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "35cf6faf442d325961935f660e2ab5a0"
		logic_hash = "856bfb47557b60f69aa1141477d6ce446ea13ebbe899022d7996ceef08bdefbb"
		score = 70
		quality = 85
		tags = ""

	strings:
		$str1 = "string.find(attachment:filename(),'obt075') ~= nil"
		$str2 = "os.execute('cp '..tostring(tmpfile)..' /tmp/'..attachment:filename())"
		$str3 = "os.execute('rverify'..' /tmp/'..attachment:filename())"

	condition:
		all of them
}

Strings (3 patterns)

Identifier	Type	Value
$str1	text	"string.find(attachment:filename(),'obt075') ~= nil"
$str2	text	"os.execute('cp '..tostring(tmpfile)..' /tmp/'..attachment:filename())"
$str3	text	"os.execute('rverify'..' /tmp/'..attachment:filename())"

Condition

all of them

In plain words (Heuristic)

All patterns in the rule must match.

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References

https://www.mandiant.com/resources/blog/barracuda-esg-exploited-globally

Sample hashes

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

35cf6faf442d325961935f660e2ab5a0

Licence & attribution

Author: Mandiant

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: 8c744b85-b61e-56d0-8a9e-ae6a954e1b95

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