alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Suspicious User-Agent (VB OpenUrl)"; flow:to_server,established; http.user_agent; bsize:10; content:"VB OpenUrl"; classtype:bad-unknown; sid:2029544; rev:1; metadata:attack_target Client_Endpoint, created_at 2020_02_27, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_02_27;)