OVER THE PAST year, the Kremlin’s strategy of weaponizing leaks to meddle with democracies around the world has become increasingly clear, first in the US and more recently in France. But a new report by a group of security researchers digs into another layer of those so-called influence operations: how Russian hackers alter documents within those releases of hacked material, planting disinformation alongside legitimate leaks.

A new report from researchers at the Citizen Lab group at the University of Toronto’s Munk School of Public Affairs documents a wide-ranging hacking campaign, with ties to known Russian hacker groups. The effort targeted more than 200 individuals, ranging from Russian media to a former Russian prime minister to Russian opposition groups, and assorted government and military personnel from Ukraine to Vietnam. Noteworthy among the leaks: A Russia-focused journalist and author whose emails were not only stolen but altered before their release. Once they appeared on a Russian hactivist site, Russian state media used the disinformation to concoct a CIA conspiracy…

But evidence that Russian hackers are fabricating their leaks could also make them less effective. Mixing fakes in with facts may work for Russian propaganda outlets. When it comes to involving US media in Russia’s influence operations, though, reporters may now think twice about trusting the contents of the next dumped inbox covered in Russian fingerprints.