ET MALWARE OSX/Shlayer CnC Activity M4

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE OSX/Shlayer CnC Activity M4";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/sd/?c="; depth:7; fast_pattern;
    pcre:"/^(?:[A-Z0-9+/]{4})*(?:[A-Z0-9+/]{2}==|[A-Z0-9+/]{3}=|[A-Z0-9+/]{4})/Ri";
    content:"&u="; distance:0;
    content:"&s="; distance:0;
    content:"&o="; distance:0;
    content:"&b="; distance:0;
    pcre:"/^\d{3,15}$/R";
    reference:url,www.carbonblack.com/2019/02/12/tau-threat-intelligence-notification-new-macos-malware-variant-of-shlayer-osx-discovered/;
    classtype:command-and-control;
    sid:2026913; rev:2;
    metadata:affected_product Mac_OSX, attack_target Client_Endpoint, created_at 2019_02_14, deployment Perimeter, malware_family Shlayer, performance_impact Low, confidence High, signature_severity Major, updated_at 2020_08_27;
)