alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Suspicious Request for Terse Numeric .dat File"; flow:established,to_server; http.start; content:".dat|20|HTTP/1.1|0d 0a|"; fast_pattern; http.uri; pcre:"/\/[0-9]{1,2}\.dat$/"; http.header_names; content:!"Referer"; content:!"Pragma"; content:!"Cache-"; classtype:bad-unknown; sid:2030225; rev:1; metadata:affected_product Any, attack_target Client_Endpoint, created_at 2020_05_27, deployment Perimeter, confidence Medium, signature_severity Informational, updated_at 2020_05_27;)