When you are contacted by a recruiter, they will give you a description of the job they want you to take, but they won't tell you the name of the employer. This ensures that they will get their cut for their "assistance" if you eventually get the job.
Luckily, recruiters are as lazy as the rest of us. If you Google the description, you can usually find the job listing or company profile.
I don't do this to screw recruiters out of their take. If I am interested in the job, I'll go through the recruiter. I just do it to save time; 90% of the jobs offered via recruiters are not worth pursuing.