According to experts at QR Code Generator, any code can be tampered with. The codes can then lead you to fake websites that can steal credit card information. This is form a of phishing, often referred to as quishing.
When scanning in a public place, like a parking lot, check if there's sticker over the original code that you're scanning.
Look for any other suspicious signs. If you're having doubts, type in the URL yourself .
You should also avoid scanning QR codes from spam emails.
Finally, check the "destination link" of any QR code. If the URL has typos, that's a sign that it could be a scam.