alert tls $EXTERNAL_NET any -> $HOME_NET any (
msg:"ET ATTACK_RESPONSE Havoc/Sliver Framework TLS Certificate Observed";
flow:established,to_client;
tls.certs;
content:"|31 0b 30 09 06 03 55 04 06 13 02|US|31 11 30 0f 06 03 55 04 08 13 08|Illinois|31 0f 30 0d 06 03 55 04 07 13 06|Aurora|31 09 30 07 06 03 55 04 09 13 00 31 0d 30 0b 06 03 55 04 11 13 04|"; fast_pattern;
pcre:"/^\d{4}[01]/R";
content:"|06 03 55 04 0a 13|"; distance:3; within:6;
content:"Debug"; nocase; distance:1; within:5;
pcre:"/^(?:\s(?:co(?:rp)?|l(?:lc|td)|inc))?[01]/Ri";
content:"|06 03 55 04 03|"; distance:3; within:5;
content:!"|2a 86 48 86 f7 0d 01 09 01|";
reference:url,github.com/BishopFox/sliver/blob/97d3da75b6e24defb3a2a97443a15a632b3a8448/server/certs/subject.go;
classtype:trojan-activity;
sid:2037608; rev:2;
metadata:affected_product Any, attack_target Client_and_Server, created_at 2022_07_07, deployment Perimeter, malware_family Sliver, malware_family Havoc, performance_impact Low, confidence High, signature_severity Major, updated_at 2024_01_03;
)