alert ip [103.198.36.0/22,103.200.28.0/22,103.214.56.0/22,103.215.80.0/22,103.225.68.0/24,103.225.69.0/24,103.228.60.0/22,103.228.196.0/22,103.229.124.0/22,103.230.24.0/22,103.232.36.0/22,103.232.200.0/22,103.236.32.0/22,103.237.86.0/23,103.240.252.0/22,103.243.240.0/22,103.248.68.0/22,103.249.72.0/22,103.250.224.0/22,103.253.216.0/22] 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: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;)