ESO network affected by cyber incident

21 May 2024

Starting on Friday 17 May, several of ESO’s network and communication services were shut down to allow for an important software upgrade to be deployed. The upgrade is being done in response to a cyber security incident. In addition to the shutdown, mitigating this threat included limiting communications regarding the incident to avoid compromising ESO’s cyber security response plan.  

As of Tuesday 21 May, email services have been restored and the ESO website is back online. Other services, such as the ESO and ALMA Science Archives, are expected to be restored in the coming days.  

ESO’s IT team is working together with a cyber security consultant on detecting and clearing malicious software from all ESO’s machines, as well as on investigating the attack and its consequences. Should any of our stakeholders be found to be affected, they will be informed immediately.   

ESO observations have not been affected since our observatories run largely on separate networks. ELT construction remains unaffected.


Bárbara Ferreira

ESO Media Manager

Garching bei München, Germany

Tel: +49 89 3200 6670


About the Announcement



A bird’s-eye view of ESO
A bird’s-eye view of ESO