TECH How to scan a QR code with your iPhone or Android phone (no apps needed) QR codes are those pixelated squares you see in restaurants, advertisements, stores, food packaging, business cards ...

The FBI and Better Business Bureau warn criminals are taking advantage of the convenience — in some cases, even sticking malicious QR codes over real ones.

Scanning a QR code with your phone is a common request, and should be simple, right? But it's not always as obvious how to do it as it should be.

Fake QR codes help cybercriminals leverage stolen information to drain bank accounts. Other QR code scams trigger repeated charges to credit cards.