alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING curl User-Agent to Dotted Quad"; flow:established,to_server; http.user_agent; content:"curl/"; startswith; nocase; fast_pattern; http.host; pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/"; classtype:bad-unknown; sid:2034567; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_12_01, deployment Perimeter, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_01;)