alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE Cobalt Strike Malleable C2 (Havex APT)";
flow:established,to_server;
http.request_line;
content:"GET|20|/include/template/isx.php|20|HTTP/1.1"; fast_pattern; bsize:38;
http.cookie; bsize:172;
content:"="; offset:171; depth:1; endswith;
pcre:"/^[a-zA-Z0-9\/+]{171}=$/";
http.user_agent;
content:" Java/";
reference:url,github.com/rsmudge/Malleable-C2-Profiles/blob/master/APT/havex.profile;
classtype:command-and-control;
sid:2029740; rev:1;
metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_03_26, deployment Perimeter, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2020_03_26, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;
)