ET MALWARE Possible TickGroup Casper CnC Activity

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Possible TickGroup Casper CnC Activity";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.user_agent;
    content:"Mozilla/4.0 (compatible|3b 20|MSIE 6.0|3b 20|Windows NT 5.1|3b 20|SV1|3b 20|.NET4.0C|3b 20|.NET4.0E)"; fast_pattern;
    http.header_names;
    content:"|0d 0a|Accept|0d 0a|Content-Length|0d 0a|User-Agent|0d 0a|"; depth:38;
    reference:url,documents.trendmicro.com/assets/pdf/Operation-ENDTRADE-TICKs-Multistage-Backdoors-for-Attacking-Industries-and-Stealing-Classified-Data.pdf;
    classtype:command-and-control;
    sid:2029096; rev:2;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_12_04, deployment Perimeter, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_24;
)