Almost half of cyber crime attacks are committed against small businesses.
Most attacks are not reported to gardaí.
This is despite the fact that cyber attacks are now seen as the fastest-growing crime, according to research compiled by Cork-based Apex Insurance, which offers firms cyber insurance.
It comes as UK retailer Dixons Carphone uncovered unauthorised access of data held by the company, involving 5.9 million payment cards.
Huge numbers of businesses and consumers are vulnerable to online attacks, Apex Insurance, a brokerage, said.
Nearly half of all cyber attacks are committed against small firms, said Apex, quoting global research firm Cybersecurity Ventures.
Close to nine out of 10 Irish people believe they are at risk of becoming a cyber-crime victim, the insurer said, quoting research carried out by the European Commission.
Four out of 10 people in this country report receiving fraudulent emails or dodgy calls from criminals seeking their personal data.
A quarter of people have discovered malicious software on an IT device. But just 5pc of cyber crimes are reported to gardaí, according to Det Supt Mick Gubbins of the Garda Cyber Crime Bureau.
The insurer forecasts 20pc growth in the cyber insurance market. Apex managing director Theo Hoare said only 10pc of SMEs here have financial protections in place to cover them in the event of a cyber attack.