alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET HUNTING Base64 Encoded Null Byte Padded File in HTML Body (Magic Bytes)"; flow:established,to_client; file_data; content:"data|3a|"; nocase; content:"base64,AAAAAAAA"; within:65; fast_pattern; flowbits:set,et.exploitkitlanding; reference:url,urlscan.io/result/98d7e72b-67b8-4d7c-9735-c27525b0a550/#transactions; classtype:misc-activity; sid:2047791; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_08_28, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Informational, tag HTML_Smuggling, updated_at 2023_10_06, reviewed_at 2023_08_28, mitre_tactic_id TA0005, mitre_tactic_name Defense_Evasion, mitre_technique_id T1027, mitre_technique_name Obfuscated_Files_or_Information; target:dest_ip;)