Ransomware is malware that freezes access to the computer system it infects. The software then demands a ransom be paid to the creator of the malware in order for the restriction to be removed.

Nova Scotia RCMP are warning the public about an online scam that targets computer users and holds their computers for a ransom in exchange for money.

The malicious software, known as ransomware, pops up on users' computers and tries to trick them into paying money to have the software removed.

"This type of pop-up goes far beyond being a nuisance and can actually harm your computer," said Cpl. Christian Hochhold of the RCMP technological crime unit.

"If you cannot access anything on the computer beyond the pop-up screen your computer is infected."

The malicious software freezes access to the computer system it infects and then demands a ransom be paid to the creator of the malware in order for the restriction to be removed.

RCMP say in some cases, the ransomware installs itself on the computer and encrypts files on the hard drive, preventing users from accessing their own files.

Once installed, the malicious software prompts a message to appear indicating the files are locked and the data will be lost unless you pay the scammer a sum of money. RCMP say this type of ransomware is very difficult for malware-scanning software to get rid of — however RCMP say people should not cave to the scammers' demands.

"Do not pay the scammers' ransom request. Be sure to frequently backup your important data in case your computer is infected and if it is, have it cleaned to remove any malware," advises Hochhold.

To prevent ransomware attacks, police advise people to:

Have a proper firewall installed on your computer.

Ensure software such as anti-malware, web browser and operating system are up to date.

Be cautious of the websites you visit.

Don't open email attachments unless your trust the source.

Regularly scan your computer for malware.

It may be possible to remove the ransomware yourself following instructions in an online search but it might be necessary to have a professional look at your computer.