While this news shouldn't surprise anyone, the UK government did its due diligence by investigating these hacks thoroughly over 18 months before publicly accusing Moscow. After careful investigation, we know the FSB has targeted high-level personnel in the UK as well as US military personnel. Furthermore, this group of Russian attackers hacked Ukrainian infrastructure months before the annexation of Crimea.
This so-called bombshell news would mean something if the US hadn't been doing the exact same thing to both private citizens and diplomats in Russia. American intelligence agencies, working in tandem with Apple, have already been using Apple-provided malware to hack iPhones via their sim cards registered with diplomatic missions. Western countries publicly decry Moscow's use of cyberwarfare, while conducting the very same malicious schemes.