Hackers are more technologically advanced than those trying to stop them, according to a survey of 500 US business executives, law enforcement services and government agencies.
Three out of four respondents to the 12th annual survey of cyber-crime trends, carried out by consultants PwC, said they had detected a security breach in the past year, and the average number of security intrusions was 135 per organisation.
The top five cyber-attack methods reported in the survey were malware, phishing, network interruption, spyware and denial-of-service attacks.
"Despite substantial investments in cyber security technologies, cyber criminals continue to find ways to circumvent these technologies in order to obtain sensitive information that they can monetise," Ed Lowery, who heads the US Secret Service's criminal investigative division, said in a written statement.
More worryingly, the survey found 28 per cent of respondents said the attackers were insiders, either contractors or current and former employees or service providers.
Lowery said companies and the government need to take "a radically different approach to cyber security", which goes beyond antivirus software, training employees, working closely with contractors and setting up tighter processes.
The survey was co-sponsored by PwC, the US Secret Service, the Cert Division of Carnegie Mellon University's Software Engineering Institute and CSO security news magazine.