Cyber attacks on electricity infrastructure are occurring more frequently but are not being reported, according to Guy Carpenter.

The reinsurance broker warns the growth of automated controls and interconnected work systems is weakening the “seal” around industrial controls for critical infrastructure, making them vulnerable to cyber attacks.

It forecasts 30 billion connected devices will be used by 2030, creating more assets susceptible to attack.

A cyber attack on the electrical grid could lead to lost revenue, penalties, repair costs and reputational damage, Guy Carpenter says.

And it warns cyber attacks are starting to hit economic and political systems as a whole, rather than targeting consumers.

Companies are also becoming more vulnerable because they are dependent on their systems and data, and interference could affect market capitalisation, leadership, sales and profit. Failures could destabilise a company overnight.

The WannaCry and NotPetya cyber attacks in 2017 were a game-changer, with losses of more than $US300 million ($421.77 million) suffered by some companies. They revealed systemic risk, hitting companies that were not specifically targeted.

Hackers are becoming more sophisticated, and terrorists have ambitious goals for cyber attacks, the broker says.

Swiss Re has previously warned cyber losses from attacks on critical infrastructure may be too great for the private market to absorb.

Insurers have started developing third-party business interruption products as the threat increases.