Appearing before a joint House subcommittee hearing, the witnesses noted that Iran has been rapidly accelerating its cyber capabilities, which the nation has been deploying both directly and through proxy groups, such as Hezbollah.

They suggested that Iran, which has been resisting mounting international pressure to submit to inspections of its nuclear program, is turning toward cyber attacks as a channel to attack corporate and government entities in the United States, noting the relative ease with which those attacks can be launched against much larger adversaries.

"Cyber basically levels the playing field. It provides asymmetry that can give small groups disproportionate impact and consequence," said Frank Cilluffo, associate vice president and director of the Policy Institute at George Washington University. "And whereas they may not have the capability they can rent or buy that capability. There's a cyber arms bazaar on the Internet. Intent and cash can take you a long way, and that is what I think we need to be thinking about."

The hearing comes as the House of Representatives is in the midst of a debate on a controversial cybersecurity bill that would create a framework for sharing information about threats to critical digital infrastructure. Several privacy and civil liberties groups have raised concerns that the bill would provide for a nearly unlimited flow of personal information to secretive military agencies with minimal oversight. The bill's authors have offered a series of changes to narrow the scope of the information-sharing system the legislation would establish, though some groups maintain their opposition.