pfbadhost

pf-badhost is a fast, bi-directional network filtering utility powered by the PF firewall. pf-badhost blocks many of the internet's biggest irritants - annoyances such as SSH and SMTP bruteforcers are largely eliminated. Shodan scans and bots looking for webservers to abuse are stopped dead in their tracks. When used to filter outbound traffic, pf-badhost blocks many seedy, spooky malware containing web hosts
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