What are you referring to? The QR code you scan to share someone's wi-fi network? Someone borrowing your phone to scan a code and visit a website? Completing a whole thought makes it easier for people to understand what you are asking.
Yes. ANY QR code can have malicious content. The code itself does not have the malicious content, but will send you to a bad site that can install malware and viruses. This is true of ANY QR code you see, so you have to keep "Bad actors" in mind at all times. If it comes from a trusted source, then it is likely OK. Is it possible that the person who gave you the code may have malicious intent? Then don't scan the code they give you. Just like you don't click on links inside a suspicious e-mail.
