To monitor your WordPress site for various types of activities, I recommend a few plugins to assist you so that you don’t have to do it manually.

For monitoring the activity of a logged in user, you can use one of the following plugins. They both provide detailed user activity logs such as when they logged in, what did they change, what did they install, etc.

  • Stream – Track and monitor every change made on your WordPress site in beautifully organized detail.
  • WP Security Audit Log – Identify WordPress security issues before they become a problem. Keep an audit log of everything that happens on WordPress including WordPress user activity.

For keeping track of file changes, one plugin stands out to help with this activity.

  • WordPress File Monitor Plus – Monitor files under your WP installation for changes. When a change occurs, be notified via email. This plugin is a fork of WordPress File Monitor.