ET MALWARE Operation Interception Beacon

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Operation Interception Beacon";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/start.html"; bsize:11;
    http.accept;
    content:"text/html,application/xhtml+xml,application/xml|3b|q=0.9,image/webp,image/apng,*/*|3b|q=0.8,application/signed-exchange|3b|v=b3"; fast_pattern; bsize:118;
    http.header_names;
    content:"Host|0d 0a|Upgrade-Insecure-Requests|0d 0a|User-Agent|0d 0a|Accept|0d 0a|Accept-Encoding|0d 0a|Accept-Language|0d 0a|";
    reference:url,www.welivesecurity.com/wp-content/uploads/2020/06/ESET_Operation_Interception.pdf;
    reference:md5,851a4f13928a5edb3859a21a8041908e;
    classtype:trojan-activity;
    sid:2030356; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2020_06_18, deployment Perimeter, confidence High, signature_severity Major, tag c2, updated_at 2020_06_18, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)