PORTLAND, Ore. -- Cases of the computer encryption virus known as ransomware are heating up across the country. Portland State University students were hit over spring break by a mass email containing the virus, and now we're learning at least eight students fell victim.

The email that has a lot of students talking was made to look like an invoice for an ambiguous online purchase. It was sent to hundreds of PSU email addresses, prompting a big warning from the school - don't click on the download link, it's a virus.

"I just got an email saying not to click on things with links to weird places and I was like duh," said Samual Salin, a PSU computer engineering major.

Eight students have come looking for help from virus scrubber and tech Peter Brown, owner of nearby Bolt Computer Services. One story stands out.

"In this situation, we had a student who had his dissertation paper on his laptop and he didn't have backups, and so what occurred was his machine was cryptolocked and they wanted over $600," Brown explained.

The college senior had no choice but to pay the money with the help of Brown securing the payment in Bitcoin, an internet currency that's difficult to track, and the student got his hard work back.

The encryption messages are popping up more and more, thanks to innocent people tricked into clicking on bad links. Cyber thieves are getting very good at sending emails that look like they're from someone you trust and regularly receive messages from. Brown says carefully read the text without clicking on any links. If the writing doesn't sound like the person you know, be careful and confirm with them whether they actually sent you the message before downloading anything.

In February, ransomware infected at least 3 Newberg-area businesses. Some paid; some didn't need to, they had their computers backed up. The same month, a Los Angeles hospital was forced to pay $17,000 to unlock their entire system from the malicious software. Then last week, a 90-year-old Portland man was a rare case for an Apple computer. He clicked on a pop-up with the virus, and paid $400.

Brown says the thieves are smart, they ask for relatively small amounts of money, less than $1,000 because they know most people will rationalize it's worth it to pay versus lose their data. And because the thieves are targeting so many people, those small amounts add up.

But the FBI warns cyberthieves are getting bolder, going after bigger computer networks, like PSU or hospital systems, even government agencies, to demand more money. Brown says the hacker can instantly see how many computers are affected by the virus, and will adjust their ransom payment amount based on how large of a network they've attacked.

"It's a situation even beyond the best technician's control," Brown said. "It is a serious, serious issue and nobody yet knows how to break these."

In order to not fall victim, Brown says to have at least two backups of your full computer. You can use a hard drive, a thumb drive or recommended programs like DropBox, CrashPlan and uBlock are great for backing up and copying all your files. But he warns, make sure your external drives are not connected to your computer after you back up. Ransomware can infect any connected drives once it takes hold.