The comments follow a June 13 announcement on the subject by Germany’s Federal Office for Information Security (BSI), which is charged with securing the German government’s electronic communications. According to the BSI, a widespread and systematic attack against Germany’s energy networks has been taking place for at least a year now. The attack, which the BSI codenamed BERSERK BEAR, consists of various efforts by hackers to compromise computer networks used by German companies that provide electricity and natural gas to consumers around the country.

The attacks have been mostly unsuccessful, said BSI, having managed to breach just a few office computer networks. Energy grids have remained largely unaffected by BERSERK BEAR, said BSI. But the agency has refused to disclose information about the extent of the alleged cyberattacks and the companies that were targeted. It claims, however, that the situation is now “under control”. On Wednesday, Hans-Georg Maassen, director of Germany’s Federal Office for the Protection of the Constitution (BfV) said in an interview that the Russian government was most likely behind the attacks. There were “numerous clues pointing to Russia”, said Maassen, including the method with which the attack was carried out. The “modus operandi” of the attackers “is a major indicator that points to Russian control of the offensive campaign”, said Maassen.

Earlier this month, the United States imposed for the first time economic sanctions on Russian companies that allegedly helped the Kremlin tap undersea communications cables used by Western countries. One of the companies was identified by the US Department of the Treasury as Digital Security, which Washington said has helped Russian intelligence agencies develop their offensive cyber capabilities. Two of Digital Security’s subsidiaries, Embedi and ERPScan, were also placed on the US Treasury Department’s sanctions list. But the Kremlin fervently denies these accusations. On Wednesday, a spokesman for the office of the Russian presidency said that Moscow had “no idea what [Maassen] was talking about”. A Russian Foreign Ministry spokesman told reporters in the Russian capital that Germany and other countries “should provide facts” to justify their accusations against Moscow.