Executive Recruiters or Head Hunters, as they are called, solicit people for jobs with companies. They use various resources or tools to find the appropriate people for job requirements that employers set. They usually gather data and look through resumes on on-line sites to find these matches. Headhunters work for a company for a commission off your potential salary or you can directly hire a headhunter for a fee. Headhunters main goal is to get you to become a client. They will do almost anything to make this happen. Become your friend, listen to your problems or promise to find you a match in your dream job.
Using elicitation for headhunters is one of there best tools. Armed with the knowledge gained from your resume and the specifics about the positions, headhunters use the art of elicitation to gain your trust and find out information about exactly what you really know how to do or what is fluffed up on your resume. As an example, a headhunter that is looking for your true skills about SQL database maintenance could pose as a colleague or a employee of a former company to ask very specific questions about how you would do database recoveries or queries to find specific data in a database.
Headhunters can also use information brokers to gather personal information about you when they are targeting you about a job opportunity. They may be able to find out that you are going through some financial trouble by looking at your credit report. With this information they could leverage that information while trying to get you into a new position that only they can setup for you.
Executive Recruiters can serve a very valuable purpose in helping people locate employment that makes them happy and makes them money. As with any field, as long as the recruiter is using ethical methods the risk to the person is very minimal.
Just to illustrate one of the dangers, which is having your information available to the world. Using a simple Google search look at what one can find. In this search we find hundreds of PDF resumes that list names, phone numbers, home addresses, birth dates, some even list social security numbers. This can make a social engineers job easier if he can locate a resume or CV on you and have all this information with little or no digging.
Another such risk is found in Security Education, Awareness, and Training: From Theory to Practice By Carl A. Roper, Joseph J. Grau, Lynn F. Fischer. On page 288 which can be found here, it talks about social engineers using the headhunter as a ploy.