News of a recent security breach in the US electrical grid is prompting new security worries and calls for better protection.

A report in The Wall Street Journal claimed that spies from China and Russia had breached security protections on US electrical grids, and installed software which could have been used to cripple systems such as water treatment centres and power plants.

The report noted that no malicious activity had taken place. However, given the severity of such an attack, security experts are issuing dire warnings that protections must be improved.

Phyllis Schneck, vice president of threat intelligence at McAfee, said that the incidents show just how deep our dependence on IT has become, and how vulnerable populations can be when electrical grids are compromised.

"A cyber event can cause a catastrophic physical event," Schneck explained. "As humans it tends to be our habit to build for availability before we put security in. This is a wake-up call in building security into every layer of our infrastructure."

The possibility of a cyber attack on public utilities is not new. Last year, the US government released the findings of its Cyber Storm 2 exercise which simulated an attack on corporate and government IT systems across a number of countries.

It was acknowledged at the time that all sides needed to improve, particularly regarding communication and interaction in the event of an attack.

Schneck maintained that the latest development only reaffirms the need to improve the understanding and protection of these government and private infrastructure systems.

"Today's story is not the first, [and] it won't be the last," she said. "We have not yet made securing these systems the priority that it needs to be."