A Barts Health malware attack forced the shutdown of hospital IT systems on Friday last week as the UK NHS Trust attempted to limit the damage caused and contain the infection.

Barts Health is the largest NHS Trust in the United Kingdom, operating six hospitals in the capital: Mile End Hospital, Newham University Hospital, St Bartholomew’s Hospital, The London Chest Hospital, The Royal London Hospital, and Whipps Cross University Hospital.

The Barts Health malware attack occurred on Friday 13, 2016. Given the number of ransomware attacks on healthcare organizations in recent months, rumors started to quickly circulate that this was another healthcare ransomware attack.

A statement was released on Friday claiming the Trust had experienced an ‘IT attack,’ and that as a precaution, a number of drives were taken offline to prevent the spread of the infection. The type of malware that had been installed was not known, although the NHS trust did say in its statement that it did not believe ransomware was involved.

Multiple drives were shut down following the discovery of the malware including those used by the pathology department, although patient data were unaffected and the NHS Trust’s Cerner Millennium patient administration system remained operational, as did the systems used by the radiology department.

Today, Barts Health reports that all of its systems are back online and the infection has been removed. Medical services for patients were not affected, although Barts Health said due to the need for requests to be processed manually, it may take a few days for the pathology department to deal with the backlog.

Barts Health also reiterated that at no point were patient medical records compromised. No mention has been made about how the malware was installed and the type of malware involved was not announced. However, the Barts Health malware attack involved a form of malware that had not previously been seen and was a ‘Trojan Malware.’

The Trust said “whilst it had the potential to do significant damage to computer network files, our measures to contain the virus were successful”.

Ransomware Attacks on UK Hospitals

In November last year, the Northern Lincolnshire and Goole NHS Trust was attacked with ransomware which resulted in IT systems at three hospitals being crippled. As a result of that attack, the NHS Trust was forced to cancel 2,800 operations and appointments while the infection was removed and systems restored. The majority of IT systems had to be taken offline, hence the major disruption to medical services.

While Locky and Samas have been used extensively in attacks on U.S. hospitals, the Northern Lincolnshire and Goole NHS Trust ransomware attack involved a ransomware variant known as Globe2 – A relativity new variant that was first identified in August 2016.

Globe ransomware has been spread primarily via spam email and malicious file attachments. Opening the file attachment triggers the downloading of the ransomware. As with other ransomware variants, the attachments appear to be files such as invoices or medical test results.

Malicious links are also used to spread ransomware infections. Clicking a link directs users to malicious websites where ransomware is automatically downloaded. Fortunately for organizations attacked with Globe ransomware, a decryptor has been developed by Emisoft, which is available for free download.

However, relatively few ransomware variants have been cracked. Recovery can also take time resulting in considerable disruption to business processes. Ensuring backups of all critical data are regularly made will ensure that files can be recovered without giving in to attackers’ demands.

Preventing malware and ransomware attacks requires multi-layered defenses. Since many infections occur as a result of infected email attachments and links, organizations should employ an advanced spam filtering solution such as SpamTitan. SpamTitan has been independently tested and shown to block 99.97% of spam email. SpamTitan will also block 100% of known malware.