snort-rules-default binary package in Ubuntu Focal amd64

 Snort is a libpcap-based packet sniffer/logger which can be used as a
 lightweight network intrusion detection system. It features rules-based
 logging and can perform content searching/matching in addition to
 detecting a variety of other attacks and probes, such as buffer
 overflows, stealth port scans, CGI attacks, SMB probes, and much more.
 Snort has a real-time alerting capability, with alerts being sent to
 syslog, a separate "alert" file, or even to a Windows computer via Samba.
 .
 This is the Snort default ruleset, which provides a basic set of network
 intrusion detection rules developed by the Snort community. They can be
 used as a basis for development of additional rules. Users using Snort to
 defend networks in production environments are encouraged to update their
 local rulesets as described in the included documentation or using the
 oinkmaster package.

Source package