A legacy process is an older procedure that keeps shaping work even after a newer system is introduced. It may be a paper approval chain, a manual exception step, or a habit carried over from an earlier platform. The process can remain in place because staff trust it, policy still requires it, or the new tool does not fit daily operations well.
In cyber security, legacy processes matter because attackers often exploit the gap between modern technology and old ways of working. If users switch between digital and manual paths, records can become inconsistent, approvals can be forged, and security controls can be bypassed through exceptions. Defenders look for these weak points by simplifying workflows, removing unnecessary manual steps, and making sure the secure path is also the easiest path to use.