alert ip [199.67.8.0/21,199.67.96.0/19,199.71.192.0/20,199.73.64.0/20,199.84.16.0/20,199.84.55.0/24,199.84.56.0/22,199.84.60.0/24,199.84.64.0/19,199.84.216.0/21,199.84.224.0/21,199.88.251.0/24,199.89.16.0/20,199.89.198.0/24,199.103.64.0/22,199.106.8.0/21,199.107.96.0/22,199.107.152.0/21,199.108.212.0/22,199.108.236.0/22] 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:4769; metadata:affected_product Any, attack_target Any, deployment Perimeter, tag Dshield, signature_severity Minor, created_at 2010_12_30, updated_at 2026_07_15;)