alert ip [103.20.72.0/22,103.20.156.0/22,103.23.12.0/22,103.24.0.0/22,103.25.88.0/22,103.27.248.0/22,103.29.120.0/22,103.30.12.0/22,103.30.40.0/22,103.32.0.0/16,103.32.132.0/22,103.34.0.0/16,103.36.64.0/22,103.37.118.0/24,103.39.108.0/22,103.40.8.0/24,103.40.52.0/23,103.40.96.0/22,103.43.140.0/22,103.44.208.0/22] 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: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;)