Hackers target corporate network infrastructure rather than home internet users.File photo. Image: Jorma Vihtonen / YleYle News15:11The Finnish Security Intelligence Service (Supo) and the Finnish Defence Intelligence Agency are warning companies about an ongoing Russian cyber espionage campaign targeting vulnerable network devices.Supo said the threat is aimed primarily at corporate network infrastructure, not the home internet routers previously highlighted.The warning forms part of a joint advisory issued on Monday by the US National Security Agency (NSA) and several Western intelligence services, which said Russian state-backed hackers have continued to exploit poorly protected network equipment.Additionally on Monday, the European Council accused Russia's Federal Security Service (FSB) of conducting a sustained campaign of malicious cyber activity against the EU, its member states and international partners, particularly Ukraine.According to the Council, the FSB has for years carried out intrusions including the infiltration of governmental networks and sabotage of critical infrastructure.Alongside Finland, countries targeted have included France, Germany, Poland, Cyprus, the Netherlands, Austria, Slovakia and Romania.The Council said the FSB's so-called 16th Centre directs several groups responsible for carrying out cyber operations. The 16th Centre is also known by names Berserk Bear, Energetic Bear, Crouching Yeti, Dragonfly, Ghost Blizzard, and Static Tundra, among others.Finnish Foreign Minister Elina Valtonen (NCP) has summoned Russia's ambassador to Finland for questioning regarding Moscow's malicious cyber activities.France, Germany and the UK also said they would summon the Russian ambassadors in their countries.