A cyber attack on the global financial services payment system could lead to economic losses of $US3.5 trillion ($5.5 trillion), according to a Lloyd’s systemic risk scenario study.

The three countries with the highest five-year economic loss from a hypothetical but plausible cyber attack are the US at $US1.1 trillion ($1.74 trillion), followed by China at $US470 billion ($743 billion) and Japan at $US200 billion ($316 billion).

Lloyd’s says a country’s vulnerability will typically be based on its level of dependence on financial payments systems for economic productivity.

Service sector economies are typically more reliant on information technology than economies dominated by agriculture or heavy manufacturing.

“As this scenario imagines an attack on payments infrastructure, we have considered e-commerce activity and the productivity of a country’s financial services and financial markets when calculating economic losses,” Lloyd’s says.

Lloyd’s says cyber attacks continue to threaten businesses and governments, with year-on-year costs around maintenance, prevention, and response to breaches increasing.

Cyber insurance is a growing market, with written premiums expected to rise to $US13-$US25 billion ($20-39 billion) by 2025 from about $US9 billion ($14 billion) last year but it is still not enough to narrow the protection gap.

Lloyd’s says growth projections for cyber premiums “represents a small portion of the potential economic losses that businesses and society face”.

“Cyber remains a risk that has the potential to affect all areas of society, as it is both a complex and connected risk impacting areas such as supply chains and geopolitics,” Lloyd’s says.