alert ip [168.151.157.0/24,168.151.158.0/23,168.151.160.0/20,168.151.184.0/22,168.151.192.0/20,168.151.208.0/21,168.151.216.0/22,168.151.220.0/23,168.151.224.0/22,168.151.228.0/23,168.151.248.0/22,168.151.252.0/23,168.181.52.0/22,168.195.76.0/22,168.196.236.0/22,168.196.240.0/22,168.198.0.0/16,168.206.0.0/16,168.227.140.0/22,169.40.60.0/22] any -> $HOME_NET any (msg:"ET DROP Spamhaus DROP Listed Traffic Inbound group 37"; 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:2400036; rev:4888; metadata:affected_product Any, attack_target Any, deployment Perimeter, tag Dshield, signature_severity Minor, created_at 2010_12_30, updated_at 2026_11_11;)