I almost used the more PC term, 'executive recruiting'. But many/most people I know refer to them as 'headhunters'. At least some in the industry object to this term, but it is still widely used by people at large.
When I was young, I thought headhunter was the coolest job title ever. Now my wife is a recruiter, and I think of her as a headhunter. My mental picture of her day is a lot more violent than reality.
Similarly nonexecutive tech talent recruiting firms are often referred to as "body shops".
Ironic terminology is pervasive in business. Recent trends toward sensitivity are shifting patterns somewhat, but the old terms still find use.