The biggest threat to the cyber security of Irish businesses comes from ransomware, according to Dell EMC.

It claims any private network can be compromised and destroyed by an attack on one individual's unsecured device.

Ransomware is a type of computer virus which locks files, a device or whole system until the user pays a ransom to the online fraudsters.

However, there is no guarantee that the files, device or system will be unlocked, even if a ransom is paid.

If the money is not paid, then the data is typically scrambled or destroyed.

According to Dell EMC, all size of organisation from SMEs up to global technology firms have been hit with ransomware attacks.

It says FBI figures for the first three months of this year show $209m was extorted by cybercriminals using ransomware.

"Generally speaking, ransomware is activated in the same way as any other malware: users are duped into opening an email attachment or following a suspicious link," said Gerry Murray, Country Manager, Dell EMC Ireland.

"To ensure you're not caught out, it's important that you delete any suspicious emails and never download an attachment or follow a URL link if you're not expecting one from a trusted sender."

Meanwhile, figures from Dell Technologies firm RSA show that during the second quarter of 2016, phishing was up 115% on the previous quarter and a startling 308% on the same quarter in 2015.

Phishing involves fraudsters attempting to obtain passwords and other sensitive information using social engineering and malware.