Managing Rules

Updating Rules

Assuming you have Internet access, Security Onion will automatically update your NIDS rules on a daily basis. If you need to manually update your rules, you can run the following on your manager node:

sudo so-rule-update

If you have a distributed deployment and you update the rules on your manager node, then those rules will automatically replicate from the manager node to your sensors within 15 minutes. If you don’t want to wait 15 minutes, you can force the sensors to update immediately by running the following command on your manager node:

sudo salt \* state.highstate

Rulesets

Security Onion offers the following choices for rulesets to be used by Suricata.

ET Open

  • optimized for Suricata, but available for Snort as well
  • free
For more information, see:

ET Pro (Proofpoint)

  • optimized for Suricata, but available for Snort as well
  • rules retrievable as released
  • license fee per sensor (users are responsible for purchasing enough licenses for their entire deployment)

To enable the ET Pro ruleset in an already installed grid, modify the /opt/so/saltstack/local/pillar/minions/<manager.sls> file as follows:

idstools:
  config:
    ruleset: 'ETPRO'
    oinkcode: 'MYOINKCODE'

Snort Community

  • optimized for Snort
  • community-contributed rules
  • free

Snort Registered

  • optimized for Snort
  • Snort SO (Shared Object) rules only work with Snort not Suricata
  • same rules as Snort Subscriber ruleset, except rules only retrievable after 30 days past release
  • free

Since Shared Object rules won’t work with Suricata, you may want to disable them using a regex like 're:soid [0-9]+' as described in the Managing Alerts section.

Snort Subscriber (Talos)

  • optimized for Snort
  • Snort SO (Shared Object) rules only work with Snort not Suricata
  • rules retrievable as released
  • license fee per sensor (users are responsible for purchasing enough licenses for their entire deployment)

Since Shared Object rules won’t work with Suricata, you may want to disable them using a regex like 're:soid [0-9]+' as described in the Managing Alerts section.

To enable the Talos Subscriber ruleset in an already installed grid, modify the /opt/so/saltstack/local/pillar/minions/<manager.sls> file as follows:

idstools:
  config:
    ruleset: 'TALOS'
    oinkcode: 'MYOINKCODE'

Other

  • not officially managed/supported by Security Onion
  • license fee may or may not apply

To add other remotely-accessible rulesets, add an entry under urls for the ruleset URL in /opt/so/saltstack/local/pillar/minions/<manager.sls>:

idstools:
  config:
    ...primary ruleset...
    ...primary ruleset oinkcode...
    urls:
      - https://ruleseturlhere