ET MALWARE Observed Karen Ransomware CnC Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Observed Karen Ransomware CnC Checkin";
    http.method;
    content:"POST";
    http.uri;
    content:"|2f|key|2f|";
    http.host;
    content:"karen|2e|"; startswith; fast_pattern;
    http.user_agent;
    content:"Go|2d|http|2d|client";
    http.request_body;
    content:"id|3d|"; startswith;
    content:"|2d|"; distance:8; within:1;
    content:"|2d|"; distance:4; within:1;
    content:"|2d|"; distance:4; within:1;
    content:"|2d|"; distance:4; within:1;
    content:"|26|key|3d|"; distance:12; within:5;
    isdataat:!513,relative;
    pcre:"/id\x3d[a-z0-9]{8}\x2d[a-z0-9]{4}\x2d[a-z0-9]{4}\x2d[a-z0-9]{4}\x2d[a-z0-9]{12}\x26key\x3d[a-z0-9]{512}/";
    http.header_names;
    content:!"Referer";
    reference:md5,f155ec35d67f746593ce8cc4e64d33e5;
    reference:url,twitter.com/fbgwls245/status/1427610307283677186;
    classtype:trojan-activity;
    sid:2033772; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_08_23, deployment Perimeter, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_23, reviewed_at 2024_06_26, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)