Equifax cannot detect exfiltration of your data because distributing your data is their line of business. Your personal details pouring out of their servers at high speeds is what always happens there, 24 hours a day.
If my business is distributing data, the number one thing I would monitor for is that I'm getting paid for the data I distribute. Data that gets distributed for free is nearly the worst thing my software can do, so I should be investing a ton in preventing it.