The question always comes up: Is this a real email/webpage/pop-up that my computer has been compromised/infected?
The likely answer: Not actually yet.
Most of these things are outright scams, looking to get you to take the bait and make the call, click the think an then...then you're compromised and infected. The real key in all this: The more urgent the message, the more likely it is to be a scam. And when it wants you to do something, and you're unsure, don't; call someone, get a second opinion. Imagine how relieved you'll be, (and not embarrased), when someone else confirms what you're thinking...it's a scam.
If someone reaches out to you on FaceBook or on email, say they're traveling and need help, don't respond to the email or message, call them. Reach out to them through another means, like a text message or a phone call; find out if they really have a problem and a need. If you can't reach them that way, you can always reply and ask them to call you to discuss it further. If it's not them, they won't call you, you know their voice.
All that said, there's more to know to be the best, first line of defense in keeping your home and work computers safe and clean. But, as an end-user, you are the first, and best defense in keeping your system clean.
Here's a site that offers a free, 1-hour course that will give you some tools for your toolbox in how to keep yourself safe:
End User Security Awareness
You will need to register with the site, but as you do that, you can un-check the box that subscribes you to their newsletter.