The BBC, British Airways and Boots have been caught up in a cyber incident that has exposed employee personal data, including bank and contact details, to hackers.
It emerged last week that a so-called zero-day vulnerability – a flaw – in the file transfer system MOVEit, produced by Progress Software, had been exploited by cyber criminals.
It had allowed the hackers to access information on a range of global companies using MOVEit Transfer.
Thousands of firms are understood to be affected.
UK-based payroll provider Zellis confirmed on Monday that eight of its clients were among them.
It did not name the organisations.
BA, however, confirmed it had been caught up in the affair.
The airline employs 34,000 people in the UK.
The BBC and Boots, which has 50,000 staff, said they had been affected too.
The broadcaster did not believe its employees’ bank details had been exposed though company ID and national insurance numbers were compromised.
The Telegraph newspaper reported that hacking was being linked to a Russia-based group.
There has been a spate of cyber attacks linked to the Russian state since the war in Ukraine began, with Western governments, agencies and companies targeted for turning their backs on Russia.
In this instance, the compromised information includes contact details, national insurance numbers and bank details.
BA told Sky News: “We have been informed that we are one of the companies impacted by Zellis’s cybersecurity incident which occurred via one of their third-party suppliers called MOVEit.
“Zellis provides payroll support services to hundreds of companies in the UK, of which we are one.
“This incident happened because of a new and previously unknown vulnerability in a widely used MOVEit file transfer tool. We have notified those colleagues whose personal information has been compromised to provide support and advice.”
A Boots spokesperson said: “A global data vulnerability, which affected a third-party software used by one of our payroll providers, included some of our team members’ personal details.
“Our provider assured us that immediate steps were taken to disable the server, and as a priority we have made our team members aware.”
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Zellis said in its own statement: “A large number of companies around the world have been affected by a zero-day vulnerability in Progress Software’s MOVEit Transfer product.
“We can confirm that a small number of our customers have been impacted by this global issue and we are actively working to support them.
“All Zellis-owned software is unaffected and there are no associated incidents or compromises to any other part of our IT estate.
“Once we became aware of this incident we took immediate action, disconnecting the server that utilises MOVEit software and engaging an expert external security incident response team to assist with forensic analysis and ongoing monitoring.”