A Moscow court on Wednesday released performance artist
Pavlensky, who has been arrested numerous times including for nailing his scrotum to Red Square, told newsmen in the court that he would not pay the fine.
He said that his legal team had vowed to appeal the verdict.
The building, in a prominent square in central Moscow, is currently used by the KGB's main successor agency, the Federal Security Service (FSB).
The court found Pavlensky guilty of vandalising an object of cultural heritage.
The initial fine was 1.5 million roubles, but the court decided to reduce to a third of that in an apparent gesture of goodwill.
Report says Pavlensky, 32, has claimed his performances are protests against the Russian government, which he says is becoming increasingly oppressive.
The trial drew parallels to that of the punk band Pussy Riot, a few members of which were sentenced to two years in prison in 2012 for performing a blasphemous ``punk prayer’’ in a prestigious Moscow Cathedral.
Pavlensky is most famous for his 2013 stunt "Fixation" in which he stripped naked and sat down on Red Square, then hammered a nail through the middle of his scrotum and into the cobblestone pavement.
He told newsmen at the time that a naked artist staring at his own shackled testicles is a ``metaphor for the apathy, political indifference and fatalism of contemporary Russian society.’’