Rule History

alert udp any any -> any 123 (msg:"ET DOS Possible NTP DDoS Inbound Frequent Un-Authed MON_LIST Requests IMPL 0x02"; content:"|00 02 2A|"; offset:1; depth:3; byte_test:1,!&,128,0; byte_test:1,&,4,0; byte_test:1,&,2,0; byte_test:1,&,1,0; threshold: type both,track by_dst,count 2,seconds 60; reference:url,www.symantec.com/connect/blogs/hackers-spend-christmas-break-launching-large-scale-ntp-reflection-attacks; classtype:attempted-dos; sid:2017918; rev:2; metadata:created_at 2014_01_03, confidence Medium, signature_severity Major, updated_at 2019_07_26;)