In the US, federal law enforcement agents have confirmed that militant group Islamic State has unsuccessfully tried to hack American electric utilities.
At a meeting of electrical power providers last week to discuss national security concerns, a section chief at the Federal Bureau of Investigation's (FBI) cyber division John Riggi described the attacks as "strong intent; thankfully, low capability."
Also speaking at the event was Caitlin Durkovich, assistant secretary for infrastructure protection at the Department of Homeland Security, who told energy company executives that "ISIL is beginning to perpetrate cyber attacks," reports CNN Money.
Islamic State 'not good at hacking'
The investigators would not reveal any details about the incidents but they did say the attacks by Islamic State were unsuccessful due to unsophisticated hacking tools.
Riggi said the FBI was able to trace the attacks through American spies that are monitoring computer networks.
He said: "We've had pretty good success actually. "Since the FBI is an intelligence agency, we rely on the help of Central Intelligence Agency and National Security Agency (NSA). We compare information with the NSA."
Mark Lemery, critical infrastructure protection coordinator, at Utah Statewide Information & Analysis Centre, commented that although domestic terror groups are active (but without the capability), the greatest concern is attacks from other countries.
Riggi of the FBI said malware found last year on industrial control systems at energy companies - including pumps and engines - were traced to the Russian government.
Outside of the US, in May 2015, Metering & Smart Energy International reported that a blackout in Southern Europe that left much of Turkey in the dark on 31 March was possibly caused by a cyber attack originating from Iran.
Reports from Bloomberg and the UK's Observer newspaper speculated that the 12-hour outage may have been due to Turkey’s support of Saudi Arabia in its dispute against Yemen.
It is believed that Parastoo, an Iranian hacker group, was responsible for the attack that left 40 million people without electricity.
Threat to US electric grid?
When Riggi raised the FBI's concern that terrorist groups will begin to buy more capability, such as malicious software, delegates at the event hosted by the North American Electric Reliability Corporation, said the fragmentation of the US power grid will protect it from a nationwide shutdown.
At worse, an attack would only take out electricity in a tiny portion of the country, reports CNN Money.