Sweden said Wednesday that a pro-Russian group with links to Russia’s security and intelligence services was behind a cyberattack on a heating plant last year. The announcement followed warnings from officials in Poland, Norway, Denmark and Latvia that Russia is attacking critical infrastructure across Europe. In what was Sweden’s first public mention of the attack, the country’s minister for civil defense, Carl-Oskar Bohlin, said it targeted a heating plant in western Sweden but the attack failed. He gave no further details. Bohlin compared it to incidents in Poland in December, when coordinated cyberattacks hit combined heat and power plants supplying heat to almost 500,000 customers, as well as wind and solar farms. Poland later said evidence indicated hackers were “directly linked to…