People outside the US/Canada who might not be otherwise eligible to be hired as a W2 or T4 equivalent employee.
If you have a US resident's stolen PII and can somehow set up a bank account to receive ACH direct deposits, and are a good enough social engineer, can possibly get hired under that name.
Hireright can also be nasty with the background checks, to the point of asking you to correct irrelevant minor typos (say, a space) in you credit file before validating your identity.