The FBI and Microsoft have seized more than 100 web domains they say Russian intelligence used for cyber-espionage, according to court documents unsealed Thursday.

The domains were allegedly staging grounds for Russia’s FSB intelligence agency in its ongoing efforts to spy on targets of interest, ranging from the U.S. Department of Energy to Russian nonprofits and media outlets critical of the Kremlin.

The FBI said in an affidavit that the websites were used as part of a “spear phishing…