alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE OSX/SHLAYER CnC Activity M2"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:2; content:"/l"; http.user_agent; content:"|20 28|unknown|20|version|29 20|CFNetwork|2f|"; fast_pattern; http.request_body; content:"cs="; startswith; pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})/R"; http.content_type; bsize:33; content:"application/x-www-form-urlencoded"; threshold:type limit, count 1, seconds 600, track by_dst; classtype:trojan-activity; sid:2038612; rev:2; metadata:affected_product Mac_OSX, attack_target Client_Endpoint, created_at 2022_08_25, deployment Perimeter, malware_family Shlayer, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_26;)