Insured losses from a global ransomware attack could reach $US27.3 billion ($37.6 billion), a Lloyd’s-backed scenario analysis shows.

Claims would follow for business interruption, cyber extortion, incident response costs, personal cyber and liability, according to the “Bashe attack” report.

“The expansion of the cyber insurance market is both necessary and inevitable,” the report says.

“Scenarios such as the ‘Bashe attack’ help insurers expand their view of cyber risks before the next event and help them create new products and services that make businesses and communities more resilient.”

The global economy could expect a $US193 billion ($266 billion) hit under the Bashe scenario, which envisages a lone malicious email infecting 30 million devices and affecting 600,000 businesses.

“This report shows the increasing risk to businesses from cyber attacks as the global economy becomes more interconnected and reliant on technology,” Lloyd’s Head of Innovation Trevor Maynard said.

“Companies must ensure they are better prepared for ransomware attacks, and that includes working with insurers to reduce the risks before they are attacked and ensure they have the right insurance cover in place to respond after the event.

“The reality for business is it’s not if you get attacked, but when.”