British intelligence agency GCHQ has acknowledged that it has conducted a "major offensive cyber-campaign" against Daesh, the BBC reports.
The director of GCHQ, the electronic and information intelligence arm of the UK government, said that an operation was conducted which hindered Daesh ability to co-ordinate attacks and suppressed its online propaganda efforts.
Director Jeremy Fleming told a cyber security conference in Manchester: "The outcomes of these operations are wide-ranging.
"In 2017 there were times when Daesh found it almost impossible to spread their hate online, to use their normal channels to spread their rhetoric, or trust their publications."
"This campaign shows how targeted and effective offensive cyber can be," he added.
The attack is the first time that the UK has carried out cyber attacks against a military enemy.
Fleming did not disclose the methods used, but claimed that the attacks had disrupted Daesh activities and destroyed networks and equipment.