He revealed that GCHQ had worked with the U.K. Ministry of Defence to conduct "a major offensive cyber campaign against Daesh," which he claimed hindered the terror group's ability to coordinate attacks and protected coalition forces on the battlefield. “We will continue to expose Russia’s unacceptable cyber behaviour.”

In his speech, Fleming also revealed that GCHQ had carried out a major cyber offensive campaign against Islamic State (IS)militants, the first time, he said, Britain had systematically and persistently degraded an enemy’s efforts as part of wider action. In his first public speech, the U.K.'s Government Communications Headquarters (GCHQ) Director Jeremy Fleming acknowledged that the agency recently coordinated a major cyber offensive operation against ISIS, significantly crippling the terrorist group's ability to recruit and coordinate attacks online. See also: Cyberwar: A guide to the frightening future of online conflict

"In 2017, there were times where Daesh found it almost impossible to spread their hate online, to use their normal channels, to spread their rhetoric or to trust their publications," said Fleming. "Much of this is too sensitive to talk about in detail, but I can tell you that GCHQ, in partnership with the Ministry of Defence, has conducted a major offensive cyber campaign against Daesh. In his criticism of Russia, Fleming said that the Kremlin is "blurring the boundaries between criminal and state activity," a charge he also leveled against North Korea, citing its reported use of WannaCry ransomware in a worldwide 2017 attack. Fleming said that Russia's apparent role in the nerve agent attack earlier this year against former Russian military intelligence officer and U.K. double agent Sergei Skripal and his daughter Yulia "demonstrates how reckless Russia is prepared to be, how little the Kremlin cares for the international rules-based order, how comfortable they are at putting ordinary lives at risk." It demonstrates how reckless Russia is prepared to be, how little the Kremlin cares for the international rules-based order, how comfortable they are at putting ordinary lives at risk.”

Fleming, a former agent in Britain’s MI5 domestic spy service, said the robust response from Britain and its Western allies, which led to both side expelling scores of diplomats, showed the Kremlin that “illegal acts” had consequences.
Ex-MI5 agent Jeremy Fleming gives his first public speech as head of GCHQ, revealing the United Kingdom launched a "major offensive cyber-campaign" against Islamic State. He also criticises Russia for actions such as launching the NotPetya virus and the poisoning of Yulia and Sergei Skripal, both actions Russia denies involvement in.