How is it even possible to fake work experience?

Context:

I was reading a post where the OP mentioned verifying fake internships, but how is that even possible? Wouldn't they verify with the companies? I can understand faking a PoR, but even that should be difficult. Faking any kind of internship should be nearly impossible. It might be possible to craft a convincing story, but if they conduct a background check, it will be exposed, regardless of how believable the story is.

And OP is from IIM-C!!!