The new report 'Shadow in the Clouds' by Canadian and American researchers found that countries around the world have been affected.
According to the report, the researchers were able to verify and recover over 700 documents that were stolen from the Indian government, including documents that were listed as restricted, classified and secret.
Among the systems leaked out could be 'Shakti', the just introduced advanced artillery combat and control system of the Indian Army and the country's new mobile missile defence system called the 'Iron Dome'.
Researchers recovered documents on Canadian visa applications that were made to the Indian consulate in Kabul.
The espionage gang even stole documents related to the travel of NATO forces in Afghanistan
However, the researchers note that there is no direct evidence that these were stolen from Indian government computers.
The report also said that 1,500 letters sent from the Dalai Lama's office between Jan and Nov 2009, were also leaked out.
The researchers noted that while there was no clear insight into the motives of the spies, "the theme appears to involve topics that would likely be of interest to the Indian and Tibetan communities."