alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE InstallFix MacOS CnC Activity M2"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:10; content:"/api/join/"; fast_pattern; http.user_agent; content:"curl"; startswith; http.header_names; content:!"|0d 0a|x-"; nocase; reference:url,pushsecurity.com/blog/installfix; reference:url,x.com/anyrun_app/status/2036799880392265928; classtype:command-and-control; sid:2068433; rev:1; metadata:affected_product Mac_OSX, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_03_25, deployment Perimeter, deployment SSLDecrypt, malware_family installfix, confidence High, signature_severity Critical, updated_at 2026_03_25, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)