It’s been a busy summer for Russian hackers. After a series of high-profile data breaches and threats, questions are being raised about the vulnerability of November’s US presidential election to cyber-interference and subversion. July saw the leak of Democratic National Convention emails, which embarrassed the Clinton campaign by revealing accusations of the party’s dirty tricks against Democrat rival Bernie Sanders. There was the infiltration of electoral registries in Arizona and Illinois, highlighting the insecurity of electronic voting systems. Both, arguably, boosted Donald Trump, the Republican nominee. Investigations into these breaches implicate Russia’s domestic and military intelligence agencies, the FSB and GRU, a charge Russia denies. But these claims have been unusually specific and backed with corroborating evidence. If true, they suggest Russia is unleashing new tools and tactics to pursue its objectives. Could it affect the outcome of the US election? And how should we understand the apparent escalation in Russian state-sponsored hacking?