alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET EXPLOIT_KIT Coruna Device Fingerprinting M4"; flow:established,to_server; http.method; content:"GET"; http.uri; bsize:2; content:"/e"; http.header; content:"x-u|3a 20|fid="; fast_pattern; reference:url,iverify.io/blog/coruna-inside-the-nation-state-grade-ios-exploit-kit-we-ve-been-tracking; classtype:trojan-activity; sid:2068091; rev:1; metadata:affected_product iOS, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_03_09, deployment Perimeter, confidence Medium, signature_severity Major, tag Exploit_Kit, tag c2, tag Coruna, updated_at 2026_03_09, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)