JERUSALEM (JTA) — Hackers believed to be from Iran used social media and a fake news website to spy on leaders of the public and private sector in the U.S., Israel, and other countries, a cyber intelligence firm said.

iSIGHT Partners said in a report released Thursday that the campaign – which it has dubbed NEWSCASTER –  has been working undetected since 2011, targeting senior U.S. military and diplomatic personnel, congressional personnel, Washington D.C. area journalists, U.S. think tanks, defense contractors in the U.S. and Israel, as well as others who are vocal supporters of Israel. Using social networking sites such as Facebook, Twitter, LinkedIn, Google+, YouTube and Blogger, the hackers, who created six “personas” who appeared to work for a fake news site, NewsOnAir.org, have been able to obtain log-in credentials to the email systems of their victims, according to iSIGHT.

At least 2,000 people have been connected to the hackers, either by establishing relationships on social networking sites or being connected to the sites by friends. The hackers also sent the leaders links to articles, which were then used to install malware on the targets’ comupters.

“Given the covert nature of cyber espionage, its impacts are often difficult to forecast or measure; however, in this instance, we expect any access obtained by the NEWSCASTER network will be ultimately exploited for intelligence value,” INSIGHT said in its report.