SIGNATURE_BASE_Brooxml_Phishing

rule SIGNATURE_BASE_Brooxml_Phishing : PHISHING FILE
{
	meta:
		description = "Detects PDF and OOXML files leading to AiTM phishing"
		author = "Proofpoint"
		id = "ccd8ab30-90a4-5d4b-8a77-dbc4669bdb95"
		date = "2024-11-27"
		modified = "2025-06-02"
		reference = "https://x.com/threatinsight/status/1861817946508763480"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/gen_brooxml_dec24.yar#L41-L54"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "884e0b65c6c8b916ca9bc28705134ae02d1705c13cf43bff78f0c9ada894b307"
		score = 65
		quality = 85
		tags = "PHISHING, FILE"
		category = "phishing"

	strings:
		$hex1 = { 21 20 03 20 c3 be c3 bf 09 20 [0-1] 06 20 20 20 20 20 20 20 20 20 20 20 01 20 20 20 06 20 20 20 20 20 20 20 20 10 20 20 05 20 20 20 01 20 20 20 c3 be c3 bf c3 bf c3 bf }

	condition:
		all of ( $hex* ) and ( ( uint16be( 0 ) == 0x504b ) or ( uint32be( 0 ) == 0x25504446 ) )
}