ET MALWARE Possible Turla Carbon Paper CnC Beacon (Fake User-Agent)

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Possible Turla Carbon Paper CnC Beacon (Fake User-Agent)";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.header;
    content:"."; distance:1; within:2;
    content:".0|3b 20|Windows NT|20|"; distance:0;
    content:"Trident/"; distance:0;
    http.user_agent;
    pcre:"/^Mozilla\/4\.0\x20\(compatible\x3b\x20MSIE\x20\d{1,2}\.0\.\d+\.\d+\.0\x3b\x20Windows\x20NT\x20/";
    content:"Mozilla/4.0 (compatible|3b 20|MSIE|20|"; startswith;
    http.start;
    content:"Cookie|3a 20|PHPSESSID="; fast_pattern;
    http.header_names;
    content:"Referer|0d 0a|";
    reference:url,www.welivesecurity.com/2017/03/30/carbon-paper-peering-turlas-second-stage-backdoor/;
    classtype:command-and-control;
    sid:2024183; rev:6;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_04_06, deployment Perimeter, performance_impact Significant, confidence Medium, signature_severity Major, tag c2, updated_at 2024_04_22, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)