Several U.S. power utilities say they face constant cyber attacks on critical systems, according to a report by two Democratic lawmakers amid warnings from the Obama administration that foreign hackers are seeking to attack the electric grid.

Congressmen Edward Markey of Massachusetts and Henry Waxman of California disclosed their findings on Tuesday as the House Energy and Commerce Committee held a hearing on cybersecurity.

In preparing the report the two asked some 160 utilities to describe their experiences fighting cyber attacks over the past five years.

More than a dozen utilities said they experienced daily, constant or frequent attempted cyber attacks, according to a 35-page report summarizing their responses.

The report cited an unidentified Northeastern power provider as saying it was under constant attack from cyber criminals as well as activist groups who have been targeting firms in the energy sector over the past few years.

A power provider from the Midwest said it experienced daily probes of its systems: “Much of this activity is automated and dynamic in nature, able to adapt to what is discovered during its probing process,” the company said.

The U.S. public has become more aware of cyber threats against the grid and other critical infrastructure since late last year, when senior Obama Administration officials began warning that foreign enemies are looking to sabotage the U.S. power grid, air traffic control systems, financial institutions and other infrastructure.

Senior administration officials say they do not know of any successful destructive attack on the grid or other key infrastructure, but fear that hackers may have the ability to do so.

A bipartisan cybersecurity bill to protect the electric grid, introduced in 2010 by Markey and Waxman, passed the House of Representatives but not the Senate. The legislation has not been taken up again since then.

(Reuters)