ET MALWARE Cobalt Strike Beacon Activity (UNC2447)

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Cobalt Strike Beacon Activity (UNC2447)";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/wp-includes/po.php"; endswith; fast_pattern;
    http.cookie;
    pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/";
    reference:url,www.fireeye.com/blog/threat-research/2021/04/unc2447-sombrat-and-fivehands-ransomware-sophisticated-financial-threat.html;
    classtype:trojan-activity;
    sid:2032943; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2021_05_11, deployment Perimeter, deployment SSLDecrypt, confidence Medium, signature_severity Major, tag c2, updated_at 2021_05_11, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)