Infosec 2012 Hacking attacks against Blighty's top firms hit a record high according to figures for 2011.
On average, each large organisation suffered 54 significant digital assaults in that 12-month period, twice the level in 2010, while 15 per cent – one in seven – had their networks successfully penetrated by unauthorised parties.
The average cost of a major security breach at a big biz last year was £110k to £250k ($177k to $403k), a figure that drops to £15k to £30k ($24k to $48k) for small businesses. SMEs were less frequently targeted with an average of one assault a month.
Chris Potter, information security partner at PricewaterhouseCoopers, said: "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."
The figures come from the 2012 Information Security Breaches Survey of 447 UK businesses by management consultants PwC and Infosecurity Europe. The poll, published every two years, is supported by UK.gov's Department for Business, Innovation and Skills. One-fifth of those surveyed are public sector organisations.
Apart from hacking, the figures show that companies are experiencing many data-protection breaches. The vast majority of firms polled (93 per cent of large organisations and 76 per cent of small businesses) experienced a security breach in the last 12 months: the most serious breaches generally resulted from failings in a combination of people, process and technology.
The survey also found customer impersonation attempts were up threefold since 2008, with financial services organisations and government bodies affected most.
Despite the prolonged economic slowdown, most organisations are spending more on security. On average, companies spent eight per cent of their IT budget on infosec, and those that suffered a very serious breach spent on average 6.5 per cent of their IT budget on security.
By contrast, 12 per cent of bosses gave a low priority to security, with one in five spending less than 1 per cent of their IT budget on information security – possibly as a result of not being able to quantify and measure the business benefits from spending cash on defences.
Potter said: "Organisations that suffered a very serious breach during the year spent slightly below the overall average on security. The key challenge is to evaluate and communicate the business benefits from investing in security controls. Otherwise, organisations end up paying more overall.
"The cost of dealing with breaches and the knee-jerk responses afterwards usually outweigh the cost of prevention."
Universities and science minister David Willetts, whose responsibilities include cyber-security issues, commented: "The survey demonstrates why the government is right to be investing £650m to improve cyber-security and make the UK one of the safest places to do business in cyberspace. We will use the findings to help design a new annual survey of cyber-security breaches beginning next year." ®