alert udp $EXTERNAL_NET any -> any 11211 (msg:"ET DOS Possible Memcached DDoS Amplification Query (set)"; content:"|00 00 00 00 00 01 00|"; depth:7; fast_pattern; content:"|0d 0a|"; within:20; endswith; threshold:type both, count 100, seconds 60, track by_dst; flowbits:set,ET.memcached.ddos; reference:url,blog.cloudflare.com/memcrashed-major-amplification-attacks-from-port-11211/; classtype:attempted-dos; sid:2025401; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Linux, attack_target Server, created_at 2018_03_01, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_19;)