alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET PHISHING Generic AiTM Fingerprint Exfil"; flow:established,to_server; http.method; content:"POST"; http.content_type; content:"application/x-www-form-urlencoded|3b|charset=UTF-8"; http.content_len; byte_test:0,<=,160000,0,string,dec; http.request_body; content:"analytics=%7B%22screen%22%3A%7B%22availWidth%22%3A"; startswith; fast_pattern; content:"RTCRtpScriptTransform"; classtype:social-engineering; sid:2071419; rev:1; metadata:attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_08_07, deployment Perimeter, deployment SSLDecrypt, confidence Low, signature_severity Major, tag Phishing, tag AiTM, updated_at 2026_08_07, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1566, mitre_technique_name Phishing;)