NEW YORK (CBSNewYork) – You check your phone and a message pops up with a phone number telling you to call the number to pay hundreds if not thousands of dollars to unlock your phone.

What should you do?

If your phone falls victim to a ransom attack, it may be tempting to just pay up. Before you do, think twice, says CBS2’s cyber security expert Siobhan Gorman.

Most experts advise against paying the ransom. There’s no guarantee a crook is going to make good on the promise to unlock your device, so you could find yourself without your phone and out the ransom money.

If you do pay, be prepared that the hacker may find a way back into your device, lock it down again, and demand even more cash.

So, how do you protect yourself and your devices against expensive and frightening ransomware attacks?

First, back up your laptops and devices frequently—every couple of weeks—so that if your device is locked down, you still have most of the files that are stored on it.

Second, take basic cybersecurity precautions like installing software updates and security patches promptly.

And, finally, don’t use free Wi-Fi, because hackers can use it as an onramp to unsuspecting devices.

We all live in a dangerous world of new cyber threats, but Gorman says you can take simple basic steps to limit the chance you’ll be held for ransom and your device on cyber lockdown.