Russian cyber attacks infecting millions of devices across the West have affected hundreds of Australian companies.

Australia, the United States and Britain accused hackers backed by the Russian Government of being responsible for the attacks in a statement on Monday.

Targets included computer routers, firewalls and other networking equipment used by government agencies, businesses and critical infrastructure operators around the globe.

Russian cyber attacks infecting millions of devices across the West have affected hundreds of Australian companies (pictured is Russian President Vladimir Putin)

The Australian businesses, affected in 2017, have been notified by the Australian Cyber Security Centre (pictured)

US and British officials warned that infected routers could be used to launch future offensive cyber operations.

'They could be pre-positioning for use in times of tension,' said Ciaran Martin, chief executive of the British government's National Cyber Security Centre cyber defense agency, who added that 'millions of machines' were targeted.

The Australian businesses, which were affected in 2017, have been notified by the Australian Cyber Security Centre, ABC News reported.

Washington and London issued a joint alert regarding the campaign by Russian government-backed hackers.

The campaign was intended to advance spying, intellectual property theft and other 'malicious' activities and could be escalated to launch offensive attacks.

It followed a series of warnings by Western governments that Moscow is behind a string of cyber attacks.

Australia, the United States and Britain accused hackers backed by the Russian Government of being responsible for the attacks in a statement on Monday (pictured is the Government Communications Headquarters, also known as GCHQ, in the UK)

The United States, Britain and other nations in February accused Russia of releasing the 'NotPetya' virus, which in 2017 crippled parts of Ukraine's infrastructure and damaged computers across the globe, costing companies billions of dollars.

The Kremlin did not immediately respond to a request for comment.

But Russia's embassy in London issued a statement citing British accusations of cyber threats from Moscow as 'striking examples of a reckless, provocative and unfounded policy against Russia.'

How to defend your home from cyber attacks The following checklist can't guarantee stopping every attack or preventing every breach. But ensuring these steps are taken will make it significantly harder for hackers to succeed. 1) Enable two-factor authentication When it's set up, the system asks for a login and password just like usual – but then sends a unique numeric code to another device, using text message, email or a specialized app. Without access to that other device, the login is refused. 2) Encrypt your internet traffic A virtual private network (VPN) service encrypts digital communications, making it hard for hackers to intercept them. 3) Tighten up your password security Subscribe to a reputable password manager that suggests strong passwords and stores them in an encrypted file on your own computer. 4) Monitor your devices' behind-the-scenes activities Many computer programs and mobile apps keep running and sending data even when they are not actively in use. 5) Never open hyperlinks or attachments in any emails that are suspicious Even when they appear to come from a friend, use extreme caution – their email address might have been compromised. - Arun Vishwanath, Associate Professor of Communication, University at Buffalo, State University of New York Advertisement

Moscow has denied previous accusations that it carried out cyber attacks on the United States and other countries.

US intelligence agencies last year accused Russia of interfering in the 2016 election with a hacking and propaganda campaign supporting Donald Trump's campaign for president.

Last month the Trump administration blamed Russia for a campaign of cyber attacks that targeted the US power grid.

American and British officials said that the attacks disclosed on Monday affected a wide range of organizations including internet service providers, private businesses and critical infrastructure providers.

They did not identify victims or provide details on the impact of the attacks.

'When we see malicious cyber activity, whether it be from the Kremlin or other malicious nation-state actors, we are going to push back,' said Rob Joyce, the White House cyber security coordinator.

Relations between Russia and Britain were already on edge after Prime Minister Theresa May blamed Moscow for the March 4 nerve agent poisoning of former Russian spy Sergei Skripal and his daughter Yulia in the city of Salisbury.

'This is yet another example of Russia's disregard for international norms and global order - this time through a campaign of cyber espionage and aggression, which attempts to disrupt governments and destabilise business,' a British government spokesman said in London.

Britain and the United States said they issued the new alert to help targets protect themselves and persuade victims to share information with government investigators so they can better understand the threat.

'We don't have full insight into the scope of the compromise,' said US Department of Homeland Security cyber security official Jeanette Manfra.

The alert is not related to the suspected chemical weapons attack in a town in Syria that prompted a US-led military strike over the weekend targeting facilities of the Russian-backed Syrian government, Joyce said.

Shortly after the announcement, the White House said Joyce would leave his post and return to the US National Security Agency.