Big banks fear that Swift faces a growing threat of Russian cyberattacks after seven of the country’s lenders were kicked off the global payments messaging system over the weekend.

VTB, Russia’s second-biggest bank, and Promsvyazbank, which finances Russia’s war machine, were among the lenders removed on Saturday from Swift as part of the West’s sanctions campaign against Moscow in response to its invasion of Ukraine.

Senior executives responsible for cybersecurity at several banks told the Financial Times that the threat to Swift, which enables banks to send trillions in payments across borders every day, could escalate if more of Russia’s lenders are expelled from the system.