ET MALWARE MSIL/EasyLocker Ransomware CnC Activity

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE MSIL/EasyLocker Ransomware CnC Activity";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    pcre:"/\/(?:countdown|check)\/[a-f0-9]{30,45}\/(?:[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})?$/i";
    http.host;
    content:"noobcrypt"; fast_pattern; startswith;
    http.header_names;
    content:!"Referer|0d 0a|";
    reference:md5,980342a5a783d7f6ce188c575d9ca97a;
    classtype:command-and-control;
    sid:2024320; rev:3;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_05_18, deployment Perimeter, malware_family Ransomware, malware_family EasyLocker, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_06, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)