That's what the SIEM does, see ones such as IBM QRadar [1]; aggregates all the logs and network flows from across your estate and then uses rules/algorithms to determine threats and security events.

From my limited understanding MozDef is more targeted at ticketing/following through from intelligence gleaned from a SIEM as most times, people then just stick it in Remedy or Jira.

[1] http://public.dhe.ibm.com/common/ssi/ecm/en/wgd03021usen/WGD...