rule RTF_Anti_Analysis_Header { meta: description = "Detects a malformed RTF document header - Anti-Analysis tricks" author = "Florian Roth" reference = "http://decalage.info/rtf_tricks" date = "2016-04-12" score = 70 condition: uint32(0) == 0x74725C7B /* {\rt */ and not uint8(4) == 0x66 /* not followed by 'f' */ } rule RTF_Anti_Analysis_Content { meta: description = "Detects a malformed RTF document header - Anti-Analysis tricks" author = "Florian Roth" reference = "http://decalage.info/rtf_tricks" date = "2016-04-12" score = 50 strings: $r1 = /[\x0d\x0aa-f0-9\s]{64}(\{\\object\}|\\bin)[\x0d\x0aa-f0-9\s]{64}/ nocase condition: uint32(0) == 0x74725C7B /* {\rt */ and $r1 }