ET DOS Likely NTP DDoS In Progress PEER_LIST_SUM Response to Non-Ephemeral Port IMPL 0x02

alert udp any 123 -> any 0:1023 (
    msg:"ET DOS Likely NTP DDoS In Progress PEER_LIST_SUM Response to Non-Ephemeral Port IMPL 0x02";
    content:"|00 02 01|"; offset:1; depth:3;
    byte_test:1,&,128,0;
    byte_test:1,&,64,0;
    byte_test:1,&,4,0;
    byte_test:1,&,2,0;
    byte_test:1,&,1,0;
    threshold:type both,track by_src,count 1,seconds 120;
    reference:url,community.rapid7.com/community/metasploit/blog/2014/08/25/r7-2014-12-more-amplification-vulnerabilities-in-ntp-allow-even-more-drdos-attacks;
    reference:url,en.wikipedia.org/wiki/Ephemeral_port;
    classtype:attempted-dos;
    sid:2019012; rev:3;
    metadata:created_at 2014_08_26, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;
)