alert tcp $HOME_NET any -> $EXTERNAL_NET [21115:21116] (msg:"ET INFO RustDesk Check NAT Type"; flow:established,to_server; dsize:6; content:"|14 a2 01 02 08 01|"; fast_pattern; reference:url,github.com/rustdesk/rustdesk/issues/594; classtype:misc-activity; sid:2044069; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_02_02, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_02_02;)