Southern Water has issued an update confirming that a recent cyber attack could put some customer and employee data at risk.

The water company has confirmed that data from a limited part of Southern Water’s server estate was stolen and is at risk following an illegal intrusion into the company’s IT systems. This arises from the utility’s ongoing investigation into suspicious activity.

Southern Water said it is continuing to work with expert technical advisers to confirm whose data is at risk. The initial assessment is that this is the case for some customers and current and former employees.

Southern Water said it has engaged leading independent cybersecurity experts to monitor the “dark web”, commenting:

“They continue to report to us that, since we were named on the cyber criminals’ site on 22 January 2024, they have found no new evidence of the data potentially involved in this cyber incident being published online. They will continue to carry out their checks for as long as is necessary.

“We take data protection and information security very seriously and, in accordance with our regulatory obligations, we are making contact with anyone whose personal data may be at risk. “

The notifications will offer security advice, as well as guidance on recommended precautionary steps and details of the support the firm is offering them.

Throughout the process Southern Water has been working with Government, regulators and the National Cyber Security Centre. It has also notified the police and the Information Commissioner's Office.

Since the incident, the company's IT security teams have worked with independent incident response experts, using enhanced monitoring and protection tools to check actively for any suspicious activity on its IT estate. Southern Water said its operations and services to customers have not been impacted.