PARIS — French judges on Friday handed prison sentences to four Bulgarian men in a first-of-its-kind trial of a suspected Russian hybrid war operation.

The group was found guilty of conspiring last year to tag the Paris Holocaust memorial with red hands in what was undoubtedly foreign “interference,” the judge said in the Paris court crowded with journalists and Russia watchers.

The stunt was “an operation coordinated from abroad with hostile intent” with the goal of “stirring up public opinion, press on existing cleavages to further fracture French society,” she added.

The four men were banned from life from French soil.

The tagging of 35 red hands on the memorial in May of last year, along with dozens of Parisian buildings, is the first of nine similar cases currently investigated by French authorities to go on trial.

The different stunts, ranging from pig heads dropped at mosques to coffins placed near the Eiffel Tower, follow a similar pattern. They involved groups of suspects coming from other countries — including Bulgaria, Serbia or Moldova — committing acts purportedly at Russia’s behest in an apparent attempt to fuel societal tensions, thereby weakening a key Ukraine ally and undermining the West’s democratic values.