alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET SCAN IBM NSA User Agent"; flow:established,to_server; threshold:type limit, track by_src,count 1, seconds 60; http.user_agent; content:"Network-Services-Auditor"; reference:url,ftp.inf.utfsm.cl/pub/Docs/IBM/Tivoli/pdfs/sg246021.pdf; classtype:attempted-recon; sid:2003171; rev:10; metadata:created_at 2010_07_30, confidence High, signature_severity Informational, updated_at 2020_04_29;)