alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Observed Uclient User-Agent"; flow:established,to_server; http.user_agent; content:"UClient|20 28|"; startswith; fast_pattern; classtype:bad-unknown; sid:2039445; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_10_19, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_10_19;)