Some hackers infiltrated and shut down a massive tunnel system in Israel last month, causing immense traffic jams for eight hours.

The attack on the Carmel Tunnels in Haifa happened twice: The hackers targeted the tunnel's camera system which caused an immediate lockdown of the roadway for 20-minutes. The attack happened again the next morning during rush hour, shutting down the roadway for eight hours, causing massive congestion.

One expert, speaking on condition of anonymity because the breach of security was a classified matter, said a Trojan horse attack targeted the security camera system in the Carmel Tunnels toll road on Sept. 8. A Trojan horse is a malicious computer program that users unknowingly install that can give hackers complete control over their systems.

The expert said investigators believe the attack was the work of unknown, sophisticated hackers, similar to the Anonymous hacking group that led attacks on Israeli websites in April. He said investigators determined it was not sophisticated enough to be the work of an enemy government like Iran.

The expert also added:

Israel's National Cyber Bureau, a two-year-old classified body that reports to the prime minister, was aware of the incident. The bureau declined comment, while Carmelton, the company that oversees the toll road, blamed a "communication glitch" for the mishap.

Prime Minister Benjamin Netyanahu had, in June, said Iran and its proxies Hezbollah and Hamas have targeted Israel's "essential systems," including its water system, electric grid, trains and banks.

"Every sphere of civilian economic life, let's not even talk about our security, is a potential or actual cyberattack target," Netanyahu said at the time.

[AP/ABC]