The UK's largest NHS Trust has admitted that it has fallen victim to a "ransomware virus attack," likely via its ancient Windows XP PC estate.
In a notice on its website, Barts Health NHS Trust warned: "We are urgently investigating this matter and have taken a number of drives offline as a precautionary measure.
"We have already established that the Cerner Millennium patient administration system and the clinical system used for Radiology are not affected. We have tried and tested contingency plans in place and are making every effort to ensure that patient care will not be affected."
A source at the Barts Health, which has four hospitals in east London: The Royal London, St Bartholomew"s, Whipps Cross and Newham, told Health Service Journal that the attack had affected "thousands of files" on the trust's Windows XP-powered PCs, adding that its file sharing system between departments has been turned off while an investigation takes place.
No further details about the attack have been revealed, but it comes just months after a ransomware attack forced an NHS Trust in Lincolnshire to cancel operations for four days in October.
In a statement released in December, Northern Lincolnshire and Goole NHS Foundation Trust said that a ransomware variant called Globe2 was to blame for the incident.
Despite these recurring attacks, NHS Trusts still haven't seen it as a sign to upgrade from Microsoft's defunct Windows XP operating system.
According to Citrix, which filed a Freedom of Information request, 90 per cent of NHS Trusts are still running Windows XP.
This data, outed in December, also revealed that 24 Trusts are still not sure when they'll migrate from Windows XP to a newer version of Microsoft's OS. 14 per cent said they would be transitioning to a new operating system by the end of 2016, while 29 per cent pledged to make the move sometime this year.
Some parts of Atacama have not received rainfall for 500 years - but a sudden deluge of water upset the Desert's delicate biological balance
Spitzer Space Telescope could not spot Oumuamua, suggesting that it is actually pretty small
Greenland crater one of the 25 largest impact craters on Earth
This long-sought progenitor star was identified in an image captured by Hubble in 2007