alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET EXPLOIT_KIT CottonCastle EK Landing EK Struct"; flow:established,to_server; content:"/3/"; http_uri; fast_pattern:only; content:"/http|3a|/"; http_uri; pcre:"/\/3\/[a-f0-9]{32}\/http\x3a\x2f/U"; classtype:exploit-kit; sid:2018536; rev:2; metadata:created_at 2014_06_05, confidence High, signature_severity Major, updated_at 2019_07_26;)