Computer-related crimes may cause as much as US$400 billion in losses annually, according to a new study that acknowledges the difficulty in estimating damages from such acts, most of which go unreported.
The study is the second to come from Intel's McAfee security unit in partnership with the Center for Strategic and International Studies (CSIS), a Washington, D.C.-based think tank.
It drew on publicly available data collected by government organizations and universities worldwide, including institutions in Germany, the Netherlands, China, Australia and Malaysia, as well as interviews with experts.
The low-end estimate of cyberattack-related losses is $375 billion, while the upper limit is $575 billion, it said.
"Even the smallest of these figures is more than the national income of most countries and governments," the report said.
In 2009, a McAfee study estimated global cybercrime costs at $1 trillion, a figure that was criticized and one that the company later said was flawed. In partnership with CSIS, McAfee released a study in May 2013 that said global cybercrime likely didn't exceed $600 billion, which is the estimated cost of the global drug trade.
The latest report acknowledges that most cybercrime incidents are unreported, few companies disclose attacks and that collecting consistent data is difficult since countries haven't agreed on a standard definition of what constitutes cybercrime.
"A few nations have made serious efforts to calculate their losses from cybercrime, but most have not," it said.
The study's authors found aggregate data for 51 countries in all regions of the world that account for some 80 percent of the world's income. Using that data to estimate a global cost but adjusted by region, the study "assumes that the cost of cybercrime is a constant share of national income, adjusted for level of development," according to the report.
The study looked at direct and indirect costs of cyberattacks, such as the loss of intellectual property, business information, the cost of securing networks, reputational damage and the costs of recovering.
The growth of the Internet and its use for business means "the cost of cybercrime will continue to increase as more business functions move online," the report said.
U.S. companies suffered the highest losses. In general, "there are strong correlations between national income levels and losses from cybercrime," it said.
"Explaining these variations lies beyond the scope of this report, but one possibility is that cybercriminals decide where to commit their crimes based on an assessment of the value of the target and the ease of entry," the report said.
Send news tips and comments to email@example.com. Follow me on Twitter: @jeremy_kirk