alert ip [199.233.85.0/24,199.233.96.0/24,199.241.0.0/21,199.245.138.0/24,199.246.215.0/24,199.248.32.0/20,199.248.48.0/21,199.248.56.0/22,199.248.60.0/23,199.249.64.0/19,199.253.32.0/20,199.253.48.0/21,199.253.224.0/20,199.254.32.0/20,199.254.190.0/24,200.0.60.0/23,200.1.0.0/22,200.1.4.0/23,200.13.64.0/20,200.22.0.0/16] any -> $HOME_NET any (msg:"ET DROP Spamhaus DROP Listed Traffic Inbound group 51"; reference:url,www.spamhaus.org/drop/drop.txt; threshold:type limit, track by_src, seconds 3600, count 1; classtype:misc-attack; flowbits:set,ET.Evil; flowbits:set,ET.DROPIP; sid:2400050; rev:4719; metadata:affected_product Any, attack_target Any, deployment Perimeter, tag Dshield, signature_severity Minor, created_at 2010_12_30, updated_at 2026_05_26;)