alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET EXPLOIT_KIT Styx Exploit Kit Payload Download"; flow:established,to_server; http.uri; content:".exe"; nocase; fast_pattern; content:"&h="; pcre:"/\.exe(?:\?[a-zA-Z0-9]+=[a-zA-Z0-9]+)?&h=\d+$/i"; http.header_names; content:!"Referer|0d 0a|"; classtype:exploit-kit; sid:2016499; rev:17; metadata:created_at 2013_02_26, performance_impact Moderate, signature_severity Major, updated_at 2024_04_22;)