alert ip [103.113.144.0/22,103.115.48.0/22,103.115.56.0/22,103.118.241.0/24,103.118.244.0/22,103.118.246.0/24,103.119.0.0/22,103.122.223.0/24,103.133.136.0/23,103.146.208.0/23,103.148.42.0/24,103.155.92.0/23,103.155.236.0/24,103.157.75.0/24,103.163.50.0/23,103.163.162.0/23,103.171.86.0/24,103.171.236.0/23,103.173.40.0/24,103.174.130.0/23] any -> $HOME_NET any (msg:"ET DROP Spamhaus DROP Listed Traffic Inbound group 21"; 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:2400020; rev:4813; metadata:affected_product Any, attack_target Any, deployment Perimeter, tag Dshield, signature_severity Minor, created_at 2010_12_30, updated_at 2026_08_28;)