Trojan malware has been blamed for the cyberattack against Barts Health NHS Trust which forced it to take computer systems offline on Friday.
A number of computer systems including those in the pathology department were taken offline as a precaution, following what's now been confirmed as a Trojan malware infection at the county's largest hospital group. How the virus infiltrated the network still hasn't been disclosed, as the investigation continues.
On Monday morning, a Barts spokesperson told ZDNet that while most systems are back up and running, file-sharing still remained offline as a precaution. The hospital has confirmed that no patient data was accessed as a result of the malware infection and that no patient appointments were cancelled.
"The virus has been quarantined, and all major clinical systems are now up and running. No patient data was affected, there was no unauthorised access to medical records, and our antivirus protection has now been updated to prevent any recurrence," a spokesperson said.
The Trust says the malware -- not ransomware, as was claimed in some reports -- had never been seen before and "whilst it had the potential to do significant damage to computer network files, our measures to contain the virus were successful".
The pathology department was taken offline as a precaution but is now operating as normal. However, the hospital notes that "it may take a day or so to deal with the backlog" which built up during the time staff needed to process requests manually.
Barts Health NHS Trust incorporates five hospitals across East London: Mile End Hospital, Newham University Hospital, The Royal London Hospital, St Bartholowmew's Hospital, and Whipps Cross University Hospital. Its workforce of over 15,000 staff provide care to millions a year.
The attack against Barts Health NHS Trust comes after a cyberattack against Northern Lincolnshire and Goole NHS Foundation Trust took three hospitals offline in November.
That incident was eventually confirmed to be a Globe2 ransomware attack, and led to the cancellation of 2,800 patient appointments the NHS Trust. There's still no word from Lincolnshire as to how the ransomware got into the system.
Hospitals are an appealing target for cybercriminals to attack, not only because of the crucial role of IT in healthcare, but also because the data held by hospitals is so vital.