Workers at Sainsbury's, Boots, Land Rover and Jaguar could face Christmas misery after a ransomware attack on the payroll company that handles their wages.
It is claimed that a week's worth of data for 150,000 supermarket workers has been lost following an attack on Kronos, an HR tool that tracks employees' hours.
This means millions of workers who rely on the system won't be able to access their weekly schedule or even clock in and out during shifts, which could wreak havoc on pay packets just ahead of Christmas.
The company that created Kronos, UKG, said it could take "several weeks" to restore availability ahead of Christmas and has told employers to use "alternative business protocols" to ensure their staff get paid on time.
This means they are most likely to manually track worker hours, creating a higher risk of mistakes, the Daily Star reports.
Ransomware can take the form of a virus which locks computer systems entirely and threatens to delete all of the files and data unless a 'ransom' is paid--usually in the form of cash or cryptocurrency.
It is unclear exactly how the ransomware attack has taken place at Kronos, although the company's vice president, Bob Hughes, said in a statement that "the investigation remains ongoing".
He said: "We deeply regret the impact this is having on you, and we are continuing to take all appropriate actions to remediate the situation."
It is hoped that bosses can take quick action to make sure hours are still being tracked properly.
A spokesperson for Sainsbury's reassured workers, saying: "We're in close contact with Kronos while they investigate a systems issue. In the meantime we have contingencies in place to make sure our colleagues continue to receive their pay."
A UKG official told BBC News : "UKG recently became aware of a ransomware incident that has disrupted the Kronos Private Cloud, which houses solutions used by a limited number of our customers."
"It had taken immediate action to investigate and mitigate the issue, alerted affected customers and informed the authorities
"We recognise the seriousness of the issue and have mobilised all available resources to support our customers and are working diligently to restore the affected services," UKG added.
