A
Google search didn't turn up anything realy applicable, unless it's a horse searh company we're talking about.
When a company comes from out of the blue and asks you for confidential information, it could be a "phish" for later identity theft.
If you must respond to them, try giving the wrong 4 numbers and see what happens.
http://www.equisearch.net/index.html
When I googled I also saw the equine ( horse ) sites.
Redid search and came up with the above URL.
The company is a member of the NYSE.
This may not be a scam.
I wish I knew more.