ET MALWARE Lyposit Ransomware Checkin 2

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Lyposit Ransomware Checkin 2";
    flow:established,to_server;
    http.method;
    content:"GET"; nocase;
    http.uri;
    content:"/ad/?"; startswith; fast_pattern;
    pcre:"/^[a-z]{1,4}\x3d[a-z0-9]+?$/Ri";
    http.header_names;
    content:!"User-Agent|0d 0a|";
    classtype:command-and-control;
    sid:2015958; rev:4;
    metadata:attack_target Client_Endpoint, created_at 2012_11_29, deployment Perimeter, signature_severity Major, tag Ransomware, updated_at 2020_04_22, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)