alert tcp $EXTERNAL_NET any -> $HOME_NET 135 (msg:"GPL NETBIOS DCERPC invalid bind attempt"; flow:to_server,established; content:"|05|"; depth:1; content:"|0B|"; within:1; distance:1; byte_test:1,&,1,0,relative; content:"|00|"; within:1; distance:21; classtype:attempted-dos; sid:2102190; rev:5; metadata:created_at 2010_09_23, signature_severity Informational, updated_at 2019_07_26;)