Two-thirds of large businesses in the UK have been targeted by cyber attacks in the past year, according to government research.
The Cyber Security Breaches Survey found that a quarter of those who suffered an attack did so at least once a month.
Digital Economy Minister Ed Vaizey said: “The UK is a world-leading digital economy and this government has made cyber security a top priority.
“Too many firms are losing money, data and consumer confidence with the vast number of cyber attacks.
“It’s absolutely crucial businesses are secure and can protect data.”
The survey said seven out of 10 attacks could have been prevented, while only a fifth of businesses understand the dangers of sharing information with third parties.
UKFast CEO Lawrence Jones warned that smaller companies should be wary of leaving themselves open to attack.
“It’s worse than people realise. It’s not just the big firms, it’s also the small companies – so if you have a business online, you have to be aware,” he said.
“It’s now easier to extort money from someone using Bitcoin because you can’t track where that money’s going. It’s untraceable and the police are powerless.”
Jones explained the nature of the increasingly sophisticated attacks.
“Ransomware is a big problem at the moment. A client of mine recently downloaded what he thought was a piece of music and it turned out to have a back door into his computer. The computer was then locked down.
“They encrypt the data so you can’t get it back – then charge you money.
“DDOS attacks are where they flood one particular website by targeting it from thousands of computers they’ve taken over.
“They then say: ‘We’ll take your e-ecommerce site offline unless you pay us X amount of money.’
“Then there’s old-fashioned hacking, where a company may not have updated their software to the latest version.”
However firms are taking measures to counter the criminals, he added.
“Companies have security for their physical assets but need to understand that the most prized asset they can have is looking after their customers’ data.
“You can go to university now and learn how to become a hacker. It’s better to have someone looking at your site who is being paid by you to try and find the problems rather than being embarrassed down the line.
“Ethical hacking is a huge growing area in internet security.”
The government is investing £1.9bn over five years to tackle cyber crime.