Pro-Russian hackers temporarily take MI5 website offline with cyber attack

Attack follows warning over targeting of Britain and other countries supporting Ukraine in escalating war

A Telegram post made by Anonymous Russia on 30 September 2022, claiming a DDoS attack that temporarily made MI5’s website unavailable (Telegram)

Pro-Russian hackers have attacked MI5’s public website, briefly causing it to go offline as the Ukrainian conflict continued to escalate.

A group called AnonymousRussia claimed responsibility for the outage on Friday morning, publishing records showing server errors at around 9am local time.

The Security Service’s website displayed a “website under maintenance” page but was functioning normally within an hour.

A source told The Independent the website was “intermittently unavailable” but had been restored.

“It had absolutely no impact on the organisation’s work,” they added. “It was only the public facing website. There was no threat to security, no secure information was accessed.”

MI5 is Britain’s domestic intelligence agency, responsible for protecting the UK, its citizens and interests against threats to national security - including hostile foreign states and espionage.

A post by Anonymous Russia’s account on the encrypted Telegram messaging app said it had launched a distributed denial-of-service (DDoS) attack.

The technique involves a malicious attempt to disrupt a targeted server, service or network using an overwhelming flood of internet traffic.

The account describes itself as the official Russian faction of the Anonymous hacking collective, which has launched cyber attacks on governments and authorities around the world.

It came as Russia announced the annexation of four areas of Ukraine after contested referendums, sparking a fresh diplomatic backlash seeing the country’s ambassador summoned by the foreign secretary.

The prime minister accused Vladimir Putin of “once again” violating international law, adding: “The UK will never ignore the sovereign will of those people and we will never accept the regions of Donetsk, Luhansk, Kherson and Zaporizhzhia as anything other than Ukrainian territory.

“Putin cannot be allowed to alter international borders using brute force. We will ensure he loses this illegal war.”

In a speech on Friday, the Russian president vowed: “People living in Luhansk, Donetsk, Kherson region and Zaporizhzhia region are becoming our compatriots forever ... we will defend our land with all our strength and all our means.”

Earlier this year, the director of GCHQ warned that Russia was looking to target countries supporting Ukraine with cyber attacks.

British officials have not yet formally attributed blame for Friday’s incident and analysis is ongoing, but it follows previous DDoS attacks by Russian actors.

The National Cyber Security Centre (NCSC) said Russia’s GRU intelligence service was involved in cyber attacks targeting Ukraine’s financial sector days before February’s invasion.

It started bolstering the British government’s defences in January, in response to increasing “malicious cyber incidents” in and around Ukraine, and tightened its guidance for companies and public organisations.

Addressing a conference in May, GCHQ director Sir Jeremy Fleming said the conflict was “spilling over” into other nations in the information and online space.

“Perhaps, the concept of a ‘cyber war’ was over-hyped, but there’s plenty of cyber about including a range of activity we and partners have already attributed to Russia,” he added.

“We’ve seen what looks like some spillover of activity affecting other countries. And we’ve seen indications that Russia’s cyber operatives continue to look for targets in countries that are opposing their actions.”

He did not name specific nations that could be targeted, but said the security services were increasing efforts to “protect the digital homeland” by ensuring the government and British businesses improve their resilience.

The UK has formed a “National Cyber Force” comprised of intelligence and defence staff aiming to increase defences, counter disinformation, supporting overseas military activity and supporting police tackling criminal gangs.

Sir Jeremy said the UK was using its capabilities in “a legally, proportionate and ethical way” and would “oppose those who do not share our core values and interests”.