alert tcp $EXTERNAL_NET any -> $HOME_NET 139 (msg:"GPL NETBIOS SMB CD..."; flow:to_server,established; content:"|5C|...|00 00 00|"; reference:arachnids,337; classtype:attempted-recon; sid:2100535; rev:7; metadata:created_at 2010_09_23, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)