Identity theft comes in all shapes and sizes, from a stranger fishing for information to a relative who rummages through your desk drawer looking for your Social Security number. It's natural to be concerned that someone might help themselves to the assets you've worked so hard to build.

Whether you're still working or drawing money from a retirement plan, there's certainly nothing harmless about identity theft. One trick employed by scammers is to make what they're doing appear harmless when they're really worming their way into your credit card account, planning to leave you with a huge bill.

Here's how it works and what you can do about it.

Phantom payments

If you regularly review your account statements (and you should), you may notice a small, unexplained charge. It could be as little as a few cents -- small enough that you don't want to waste the time looking into it.

These tiny charges are called "phantom payments," and they could be a warning sign that someone is confirming the account is active. Once they're sure about this, these cybercriminals will follow up with larger fraudulent charges.