alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Gootkit Checkin User-Agent 2"; flow:established,to_server; http.header; content:"Gootkit ldr"; classtype:command-and-control; sid:2014021; rev:3; metadata:created_at 2011_12_13, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_20;)