alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Terse Request for .txt - Likely Hostile"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".txt"; endswith; bsize:6; fast_pattern; http.header_names; content:!"Referer"; classtype:bad-unknown; sid:2034581; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_12_03, deployment Perimeter, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_03;)