alert tcp $HOME_NET 139 -> $EXTERNAL_NET any (msg:"GPL NETBIOS SMB repeated logon failure"; flow:established,to_client; content:"|FF|SMB"; depth:4; offset:4; content:"s"; within:1; content:"m|00 00 C0|"; within:4; threshold:type threshold,track by_dst,count 10,seconds 60; classtype:unsuccessful-user; sid:2102923; rev:5; metadata:created_at 2010_09_23, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_08;)