The Flame malware attack, which was called the "most malicious" ever launched, was developed by the US and Israel to combat Iran's nuclear research, it has been claimed.
After its discovery the malware was labelled the world's first online "super-weapon".
The Washington Post reported that the US and Israel co-developed Flame to slow the development of Iran's suspected nuclear arsenal, and reduce the need for a conventional attack.
The attack, which was discovered in May, was able to control computers remotely, download information, compromise nearby devices with Bluetooth, map locations and record and send back audio.
Speculation had been mounting over who is responsible for Flame, after researchers said only a nation state would have the resources necessary to create it.
The UN recently said due to its complexity it was likely a government was behind the attack, something researchers have also claimed.
The Washington Post quoted a former intelligence official, who said that the US and Israel were responsible.
The newspaper said the program was created five years ago under the codename "Olympic Games", and that the CIA, NSA and Israeli military were involved.
The quoted official added other viruses and tools may already be in place - and that the discovery of Flame was not necessarily the end of the program.
"It doesn't mean that other tools aren't in play or performing effectively," the official said.