alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Suspicious User Agent 3653Client"; flow:established,to_server; http.user_agent; content:"3653Client"; startswith; classtype:trojan-activity; sid:2013390; rev:3; metadata:created_at 2011_08_10, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_02_07;)