alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE StealC_V2 CnC Activity (POST)"; flow:established,to_server; urilen:14; http.method; content:"POST"; http.uri; content:"/save_keys.php"; fast_pattern; http.user_agent; bsize:11; content:"Mozilla/5.0"; http.request_body; content:"keys=[FILE]"; startswith; content:".dll|0d 0a|KEY|3a 20 20|"; distance:0; threshold:type limit,count 1,seconds 300,track by_src; classtype:trojan-activity; sid:2066360; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_12_17, deployment Perimeter, deployment SSLDecrypt, malware_family Stealc, confidence High, signature_severity Critical, tag c2, updated_at 2025_12_17, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)