The London Stock Exchange (LSE) is investigating a terrorist cyber-attack on its headquarters last year while US officials have traced an attack on one of its exchanges to Russia, according to the British newspaper.
Officials suspect the attacks were designed to spread panic among markets and destabilise western financial institutions.
Cyber attacks on governments and companies increased more than 500 percent over the last two years and a raid on the European Emissions Trading Scheme ten days ago shut down the carbon market.
A leading UK cyber security expert told the newspaper: "Make no mistake, the UK’s critical infrastructure is under attack. The threat is advanced and persistent."