Hackers have hit a record number of UK businesses in the last year, according to a PricewaterhouseCoopers and InfoSecurity survey.
In a report launched in time for this year's InfoSec event in London, PwC states that one in seven large UK businesses was hacked last year. The average such business faces a significant attack every week.
But while the risks are heightening, some businesses are entirely failing to keep up in their protection attempts. A fifth of firms spend less than one percent of their IT budget on security.
As a result, hacking costs UK businesses billions of pounds in total every year, according to the PwC report, which was based on a survey of executives at 447 businesses.
Last year, each large organisation suffered 54 significant attacks by an unauthourised outsider, twice the level in 2010. Some 15 percent of large organisations had their networks successfully penetrated by hackers.
The average immediate financial cost of a large organisation's worst security breach of the year was up to £250,000. The reputational damage is often cited as being worse.
Chris Potter, PwC information security partner, said: "The UK is under relentless cyber attack and hacking is a rising risk to businesses. The number of security breaches large organisations are experiencing has rocketed and as a result, the cost to UK plc of security breaches is running into billions every year."
He added: "Large organisations are more visible to attackers, which increases the likelihood of an attack on their IT systems. They also have more staff and more staff-related breaches which may explain why small businesses report fewer breaches than larger ones. However, it is also true that small businesses tend to have less mature controls, and so may not detect the more sophisticated attacks."