A major US public utility was compromised by a brute-force attack that managed to bypass security settings and infiltrate systems, it has been revealed.
The incident was made public by the Industrial Control Systems Cyber Emergency Response Team (ICS-CERT), which forms part of the US Department for Homeland Security (DoHS).
In an update on activities for the first quarter of 2014 (PDF) the CERT team revealed that it worked with the unnamed utility to analyse the attack type and methods used and provide post-event mitigation.
"After notification of the incident, ICS-CERT validated that the software used to administer the control system assets was accessible via internet-facing hosts," it said in the notice.
"The systems were configured with a remote access capability, utilising a simple password mechanism; however, the authentication method was susceptible to compromise via standard brute-force techniques."
The notice added that investigations found "previous intrusion activity", although it did not elaborate on what this was or when it occurred. The organisation was given post-event guidance on how to better defend against such incidents.
"ICS-CERT conducted an onsite cybersecurity assessment in response to this incident to assist the asset owners with evaluating the overall security posture of their infrastructure," it said.
"In addition, ICS-CERT made practical recommendations for re-architecting and securing the control network."
As well as the public utility incident the CERT team also revealed that a second incident saw a Scada system infiltrated by a "sophisticated threat actor" who targeted an unsecure, internet-connected system.
"The device was directly internet accessible and was not protected by a firewall or authentication access controls. At the time of compromise, the control system was mechanically disconnected from the device for scheduled maintenance," it said.
"ICS-CERT provided analytic assistance and determined that the actor had access to the system over an extended period of time and had connected via both HTTP and the Scada protocol."
Further analysis found that no attempt to manipulate the system or run unauthorised controls was made.
The CERT team urged organisations to recognise the need for perimeter security tools to stop similar incidents occurring in the future.
The fact that the attacks have been made public, even with names of those affected not included, is notable as such incidents are usually kept under wraps. However, the ICS-CERT and DoHS may well be keen to underline to industry that such threats are very real and need active consideration to avoid similar scenarios.
The cost of data breaches and system infiltrations can be huge. US retail giant Target had data on some 70 million customers stolen, costing the chief executive his job, while recent UK government data said that data breaches can cost £1.15m per incident.
Dan Worth is the news editor for V3 having first joined the site as a reporter in November 2009. He specialises in a raft of areas including fixed and mobile telecoms, data protection, social media and government IT. Before joining V3 Dan covered communications technology, data handling and resilience in the emergency services sector on the BAPCO Journal.