The Nine Network has suffered what it describes as the largest cyber attack on a media company in Australia’s history, which the federal government says is a lesson for all businesses.

“Whether it’s criminal sabotage or the work of a foreign nation is still being investigated, but this attack could reveal a nationwide vulnerability,” 9News Australia tweeted.

While Nine called in the nation’s cyber detectives, Parliament House pulled the plug on the federal email network at the weekend in response to a suspected cyber attack.

Both incidents are under investigation by the public face of the Australian Signals Directorate, the Australian Cyber Security Centre.

Acting Defence Minister Marise Payne said the lead cyber security agency was very focused on working with businesses to make sure they are protecting themselves.

“This is a salutary reminder that no one is immune,” Senator Payne said on Monday.

Attackers also targeted the parliamentary email network.

Parliament’s email network was shut down over the weekend due to a fault that Assistant Defence Minister Andrew Hastie said was linked to an external provider.

The connection to government systems was severed immediately as a precaution.

“The government acted quickly, and we have the best minds in the world working to ensure Australia remains the most secure place to operate online,” he said.

Parliament’s outage followed the Nine Network confirming it was the target of a cyber attack over the weekend, disrupting its live programming out of Sydney, and an attack on Western Australia’s Parliamentary Services Department earlier in March.

Shadow treasurer Jim Chalmers said the latest cyber attack on Nine was concerning.

“What we’re hearing about here is a serious, and sophisticated, targeted attack on a media organisation.”

The Australian broadcaster was unable to air its Weekend Today and Sunday Sports programs on Sunday morning and later attributed the outage to an attack on its systems.

In a note to staff, Nine’s director of people and culture Vanessa Morley directed all employees across the country to work from home until further notice.

“Our IT teams are working around the clock to fully restore our systems which have primarily affected our broadcast and corporate business units,” she wrote.

“Publishing and radio systems continue to be operational.”

Ms Morley asked office workers to work from home using their own internet networks.

Nine’s National Rugby League coverage, 6pm news bulletins and Sunday night coverage went ahead as planned as the company enacted contingency arrangements.

The ACSC is urging organisations using Microsoft Exchange to urgently patch a number of vulnerabilities so they’re not exposed to potential compromise.

-AAP