Washington ( CNN ) -- A highly complex computer attack that may have been targeting Iran 's nuclear power plants is posing a serious security threat to critical infrastructure worldwide , according to government and cyber-industry experts testifying Wednesday on Capitol Hill . The computer worm known as Stuxnet was discovered this past July and specifically targets computers that run critical infrastructure such as the electric power grid , water treatment and oil and gas pipelines . The head of the Cybersecurity Center at the Department of Homeland Security said Stuxnet is an incredibly large , complex threat with capabilities never seen before . `` This code can automatically enter a system , steal the formula for the product you are manufacturing , alter the ingredients being mixed in your product , and indicate to the operator and your anti-virus software that everything is functioning as expected , '' Sean McGurk told the Senate Homeland Security Committee . McGurk called the development of Stuxnet a `` game changer . '' McGurk said there is not enough knowledge to identify what specifically was the target of the attack . `` To say it was specifically designed to target a particular facility is very difficult for anyone to say with assurance , '' said McGurk . However , a study by the Symantec Corporation , a cybersecurity firm , indicated Iran 's nuclear plants could be the intended target . `` Stuxnet is a threat targeting a specific industrial control system likely in Iran , such as a gas pipeline or power plant , '' according to the report . Symantec official Dean Turner told the lawmakers that `` even if something like this is tied to one particular country or group of countries , the ability of it to have a global reach is enormous . '' He said there were approximately 44,000 unique Stuxnet infections worldwide with 1,600 of them in the United States . Nearly 60 percent of the global infections were in Iran . Who was behind the attack also remains a mystery . DHS 's McGurk said the department 's analysis of the code did not point to where it was developed . The Symantec study did not identify a source of the attack . The sophistication of the malware makes it unlikely it could easily be duplicated by others . `` Stuxnet has such complexity requiring significant rescues to develop that few attackers will be capable of producing a similar threat , '' Turner said . The discovery of Stuxnet was a wake up call to government and industry , agreed all those who testified . Michael Assante , the president of the National Board of Information Security Examiners said , `` We 're not only susceptible , but we 're not very well prepared . '' Enhanced cooperation between the federal government and private sector was cited as one key component to fending off cyber threats . Sen. Joseph Lieberman of Connecticut , the chairman of the Senate Homeland Security Committee , lamented that critical cybersecurity legislation needed to combat cyber threats will have to wait until the new Congress convenes next year . `` I 'm sorry to say it seems unlikely we can pass this bill in this lame-duck session , although we should . I 've been disappointed that the administration and some other committees that have an interest in this issue have been slow to engage , '' said Lieberman .
A Senate panel hears testimony about a new computer worm . The U.S. government has been warned that the Stuxnet virus is spreading to computers around the world. The Department of Homeland Security 's cybersecurity chief calls it a `` game changer ''