ET MALWARE Tick Group Payload - Submitting Encrypted Data to CnC

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Tick Group Payload - Submitting Encrypted Data to CnC";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/?";
    content:"=A1f"; endswith; fast_pattern;
    http.user_agent;
    content:"|28|Windows|20|NT|20|6.1|3b 20|WOW64|3b|";
    http.request_body;
    pcre:"/^[a-z0-9/=\+]$/i";
    reference:url,blog.trendmicro.com/trendlabs-security-intelligence/operation-endtrade-finding-multi-stage-backdoors-that-tick/;
    classtype:command-and-control;
    sid:2029082; rev:2;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_12_02, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag TickGroup, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_03_24;
)