With more and more people being on the job market, I thought I would bring this to your attention.
At first glance, (actual email I got this morning scroll down) this appears to be a lazy recruiter bringing a new opportunity to my attention. However as we scroll down the list of information asked for, we come to the red box. First off, there is no legitimate need for any part of a Social Security Number at this stage of the recruitment process. Speaking as a Recruiter, we don't need it yet. A SSN will be given on an application and more likely AFTER an offer has been extended. Now, if you are on the phone, they will tell you (because I have had the conversation) that it will be used by their client company's ATS (Applicant Tracking System) as a unique identifier.
A quick note about ATS's, they look for duplicates by name, phone number, and email so it should be apparent if your information is being duplicated in the system itself.
In my estimation, this an attempt to gather information and steal your identity. I have posted a few times about protecting the last four of your SSN, and have added a link to a couple of articles below.
If you ARE on the market, please protect yourself. If you have questions about your job search or want a second opinion if something sounds fishy, a lot of recruiters and I'm sure HR folks would gladly give you a quick review of the scenario and their opinion on its legitimacy.
NO legitimate Recruiter HR person wants you to fall prey to some scavenger trying to steal your identity.