alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO Doc Template Downloaded from DDNS Site"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".dot"; endswith; http.host; content:".ddns.net"; fast_pattern; http.header_names; content:!"Referer"; classtype:bad-unknown; sid:2035078; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_02_03, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_02_03, reviewed_at 2023_08_25;)