- https://www.snort.org/downloads/community/community-rules.tar.gz
Beware, around 2600/3500 rules are not active by default.
- https://rules.emergingthreats.net/open/suricata/rules/
- https://rules.emergingthreats.net/open/suricata/emerging.rules.tar.gz
Updated daily.
Free, you only need to be registered to get signatures of the commercial edition with a delay of 30 days.
- https://sslbl.abuse.ch/blacklist/sslblacklist.rules
Snort is not supporting SSL fingerprinting at the moment.
- https://zeustracker.abuse.ch/blocklist.php
- zeus.rules https://zeustracker.abuse.ch/blocklist.php?download=snort
Already included in the emerging rules.