Current and former civil servants are often attractive targets because of their experience, and can be sent fake offers of consultancy work if they connect with unknown users.

At the time they warned there was a risk some Russian criminal hackers “have recently publicly pledged support for the Russian government” and that they could be willing to engage “in retaliation for perceived cyber offensives against Russia.

The NCSC said the interrupted scams included fake celebrity endorsements and bogus extortion emails. It stressed, however, that the increase in detection reflected aggressive targeting by the unit rather than an increase in scams.

Britain’s computerized army recruitment system has been closed for most of the war in Ukraine after candidate data was compromised in a possible hack, prompting alarmed officials to suspend its operations.

Australia’s electronic spy agency will double in size and ramp up its ability to launch its own offensive cyber operations as part of a $10bn national security budget pledge curiously dubbed Redspice.

Responding to cyberattacks and building national cyber resilience has never been – and will never be – the sole responsibility of governments. It requires a whole-of-society approach grounded in international cooperation efforts.

Air Marshal Edward Stringer, who left the armed forces in August, told Sky News the attack, which was discovered in March 2021, meant the Defence Academy was forced to rebuild its network.

The National Cyber Security Centre (NCSC) said it tackled a record number of cyber incidents in the UK over the last year, with ransomware attacks originating from Russia dominating its activities.

Researchers have found new evidence that suggests spyware made by an Israeli company that was recently blacklisted in the US has been used to target critics of several autocratic regimes.

The party said the impact of the incident, affecting an external supplier, was not yet clear and it was urgently investigating whether the data had been hacked. Police, cybersecurity specialists and regulators had been notified, it added.