The public are being warned to be wary of suspicious emails or text messages following a "significant increase" in the number of ransomware attacks reported to gardaí this year.
Ransomware is a form of malware in which a person's files and data are encrypted by cybercriminals. The attacker usually gains access through a victim clicking on a hyperlink or file attachment.
Thereafter, the victim then loses access to his or her data. The cybercriminal will then supply instructions for a payment to restore access to the data.
Rather than demand cash or bank transfer payment, the attacker will usually demand payment through bitcoin.
Payment demands can range from the equivalent of hundreds to millions of euro.
Detective Chief Superintendent Paul Cleary says gardaí have been notified of dozens of attacks on Irish businesses of all sizes, as well as on private individuals, this year.
"Cybercriminals are constantly on the lookout for new ways to extract money from victims," he said.
"The impact of these attacks can be crippling to a business of any size, as it prevents the victim from having any access to essential data, such as customer information, or being able to carry out even the most basic tasks, like email."
Det. Garda Cleary says anyone targeted should not engage with the cybercriminals in any way, or pay any ransom.
"There is no guarantee that your data will be released and you can find yourself receiving more demands once you make the first payment," he said.
To limit exposure to ransomware, gardaí recommend a number of actions:
- Firstly, businesses and individuals should establish a safe and up-to-date data backup, separate from their normal network or computer system.
- Updates to antivirus software and computer systems should only ever come from official sources.
- Attachments or links in emails, instant messages or text should never be opened or clicked on unless the source is known and trusted.
- Gardaí also advise that people do not mix data from work and personal online activity.
- Lastly, extreme caution should be exercised by anyone remotely accessing their company's network.
Anyone who has been the victim of a ransomware attack should report it to their local garda station immediately.