At the moment, you have to pay extra attention to scam calls, which look like a Danish phone number with +45 in front.

The phone number starts with +45 and then with 7 or 9 digits afterwards.

Danish numbers are +45 with 8 subsequent digits.

The calls are typically made from China, where a computer is set to call an arbitrary Danish number series. If you answer the phone, it will be hung up immediately.

Their intention is to get people to call you back, after which your call will be billed at a high rate.

So either check the number or avoid calling back.