alert ip [103.157.75.0/24,103.163.50.0/23,103.171.86.0/24,103.171.236.0/23,103.173.40.0/24,103.174.130.0/23,103.175.229.0/24,103.176.192.0/23,103.177.228.0/23,103.177.238.0/23,103.179.148.0/24,103.180.180.0/23,103.184.162.0/23,103.185.134.0/23,103.185.162.0/23,103.192.184.0/22,103.192.228.0/22,103.193.148.0/24,103.193.150.0/24,103.193.184.0/22] 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: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;)