Several banks have been targeted in cyber attacks in the past six months, disrupting services and highlighting the vulnerabilities of their IT infrastructure.
In its 'Financial Stability Report', the Bank of England warned that continued attacks against UK financial institutions could result in "significant" costs for the sector.
"Cyber attack has continued to threaten to disrupt the financial system. In the past six months, several UK banks and financial market infrastructures have experienced cyber attacks, some of which have disrupted services," the BoE said.
"While losses have been small relative to UK banks’ operational risk capital requirements, they have revealed vulnerabilities. If these vulnerabilities were exploited to disrupt services, then the cost to the financial system could be significant and borne by a large number of institutions."
The report states that bank vulnerabilities are largely due to a high degree of connectedness, centralised market infrastructure and "complex IT systems".
The BoE said that a programme of work has now been developed to "assess, test and improve the financial system’s resilience to cyber attack".
The report follows a meeting of the Bank’s Financial Policy Committee (FPC) earlier this year, where regulators were called to ensure that “concrete plans” are put in place by UK bank leaders to deliver a high level of protection to rapidly evolving cyber threats.
A recent exercise dubbed 'Operation Waking Shark 2' was conducted to simulate an attack on payment providers, banks and markets to find weaknesses in defence strategies, communications, and procedures.
The BoE's executive director of financial stability, Andrew Haldane, claimed that cyber attacks are being taken increasingly seriously by leaders at the large UK banks, presenting a greater threat than the Eurozone crisis.