alert http $EXTERNAL_NET any -> $HTTP_SERVERS any (msg:"ET WEB_SERVER Heimdallbot Attack Tool Inbound"; flow:established,to_server; http.header; content:"Heimdallbot"; nocase; fast_pattern; threshold:type limit, count 1, seconds 60, track by_src; classtype:web-application-attack; sid:2020323; rev:5; metadata:created_at 2015_01_28, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_11;)