ET MALWARE Tortoiseshell/SysKit CnC Activity

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Tortoiseshell/SysKit CnC Activity";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:!"&";
    content:!".";
    http.request_body;
    content:"ip="; depth:3;
    content:"#"; distance:0;
    content:"&os="; distance:0;
    content:"#"; distance:0;
    content:"&os_name="; distance:0; fast_pattern;
    content:"#"; distance:0;
    content:"&mac="; distance:0;
    http.header_names;
    content:!"Referer";
    content:!"User-Agent";
    reference:md5,a194e3bf830104922295c37e6d19d9a2;
    reference:url,blog.talosintelligence.com/2019/09/tortoiseshell-fake-veterans.html;
    reference:url,symantec-enterprise-blogs.security.com/blogs/threat-intelligence/tortoiseshell-apt-supply-chain;
    classtype:command-and-control;
    sid:2028618; rev:2;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_09_24, deployment Perimeter, performance_impact Moderate, confidence High, signature_severity Major, updated_at 2020_09_02;
)