University College London, one of the world’s leading universities, has been hit by a major cyber-attack.
The attack is thought to have been made through a so-called “phishing” email, intended to downloaded malware on to the university’s computer systems.
Access to online networks is still being limited, with the attack continuing on Thursday morning.
The university has warned of the risk of data loss and “very substantial disruption”.
UCL has the status of a “centre of excellence in cyber-security research”, awarded by the GCHQ intelligence and monitoring service.
The central London university, ranked last week in the world’s top 10, says that a “widespread ransomware attack” began on Wednesday, using emails sent to university addresses.
Ransomware attacks are where organisations are computer systems are locked and threatened with destructive software unless payments are made.
Students and staff were warned that “ransomware damages files on your computer and on shared drives where you save files” and were told not to open any suspicious attachments.
The university says that it believes the risk of further infection has been contained, but it is urging staff and students to help with efforts to reduce any “further spread of this malware”.
Universities, which can carry out commercially sensitive research, have become frequent targets for cyber-attacks.
Last month, the National Health Service in England and Scotland was subject to a significant ransomware cyber-attack, as part of an attack on institutions in many countries around the world.