The only way to do what you are asking is by using an action to run a script or software that will do this for you or by using BigFix to manage another agent -> server program.
Identity Finder is one that is both something you could run an on-demand scan using BigFix, as well as something you can manage an ongoing agent -> server relationship with BigFix. There are already analyses on BigFix.me for auditing Identity Finder.
You can look for text within a set of files using relevance, but you should definitely not do this to search all files. It will not work and it will cause the client to timeout running the relevance. It will also put unusually heavy load on the client and make it slow to process new relevance.
See related posts:
- 2 parts: Find Files vs Dir /s /a ; How to store "find files" results in a file
- File search return error
- Parsing file.txt and if exist one of value in folder
- Trying to exclude a directory from descendants search
- Relevance issues
- IllegalFileName check (or Continuing on Error)
- Regex to find files with social security numbers
- Find a file in the server \ pc