A lengthy report by the University of Toronto’s Citizen Lab details a global espionage campaign involving email phishing attacks and leaked falsified documents.

Although there is no “smoking gun” so to speak, there is overlap with previously reported Russian activities, the report released Thursday suggests.

The report focuses in part on what the authors have termed “tainted leaks,” or the act of leaking stolen documents that are otherwise authentic, but have been manipulated in certain parts to achieve a particular goal — in this case, a political one.

Starting with the successful phishing attack against an outspoken Russian journalist, David Satter — whose emails were selectively modified and published online — Citizen Lab’s researchers believe the same actor had targeted another 218 distinct users spanning 39 countries.

The targets span members of government — including “a former Russian prime minister, members of cabinets from Europe and Eurasia, ambassadors, high ranking military officers, CEOs of energy companies” — but also members of civil society organizations, such as academics, activists, journalists and employees with non-governmental organizations.

“While we have no ‘smoking gun’ that provides definitive proof linking what we discovered to a particular government agency (a common challenge in open source investigations like ours), our report nonetheless provides clear evidence of overlap with what has been publicly reported by numerous industry and government reports about Russian cyber espionage,” wrote Citizen Lab director Ron Deibert in a blog post accompanying the report .

U.S. intelligence officials believe Russian-backed groups conducted a series of cyberespionage campaigns in an attempt to interfere with and potentially sway the outcome of the 2016 presidential election.