alert http $EXTERNAL_NET any -> $HTTP_SERVERS any (msg:"GPL SCAN nessus 2.x 404 probe"; flow:to_server,established; http.uri; content:"/NessusTest"; nocase; reference:nessus,10386; classtype:attempted-recon; sid:2102585; rev:4; metadata:created_at 2010_09_23, signature_severity Informational, updated_at 2020_04_21;)