alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE KPOT Stealer Initial CnC Activity M5"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/api.php?id="; fast_pattern; pcre:"/^[A-F0-9]+$/Rsi"; http.content_type; bsize:33; content:"application/x-www-form-urlencoded"; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:md5,1ea7d46d94299fa8bad4043c13100df0; classtype:command-and-control; sid:2033397; rev:3; metadata:attack_target Client_Endpoint, created_at 2021_07_23, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_30;)