The perpetrators are urging victims to support the YouTube star and protect their systems.Read more
BBC Cyber-security reporter
Financial services firms reported a 138% rise in technology outages over the past year with an 18% increase in cyber incidents, according to The Financial Conduct Authority.
It said nearly half of firms are "still relying on ageing IT systems" with many outages linked to re-platforming and outsourcing failures.
"The most prominent of these is perhaps TSB’s information technology (IT) migration earlier this year," it said.
Megan Butler, the watchdog's executive director of supervision, said: "We are worried that a lot of firms seem overly-confident about their ability to manage flagship IT change programmes and keep their systems up to date.
"Yet this is a level of confidence that simply isn’t supported by the data we’ve collected on the ground."
Shares in challenger banking group CYBG have fallen more than 8% after profits disappointed.
CYBG, which owns Clydesdale Bank and Yorkshire Bank, swung to a full-year loss after it was forced to take an extra £150m charge linked to the mis-selling of payment protection insurance.