A global cyber attack that has played havoc with computers across Europe and Asia is believed to have wormed its way into its first Australian business, with fears more could be affected.
The government's cyber security advisor says people may switch their work computers on this morning to find their system has been impacted.
"There has been a report to the Australian cyber security centre of one instance of what we believe to be this ransomware"
The software takes over the computer's screen and blocks users from access, until they cough up with payments.
As for which Australian business has been affected?
Cyber Security Minister Dan Tehan says he's been told of the private sector being impacted, but not commonwealth organisations.
"We're not talking about a government organisation or a hospital or anything like that."
The attack has so far hit more than 100,000 computers in at least 150 countries.
Tech expert Lior Rauchberger says the criminals target people ho have outdated versions of Windows or security software.
"They find some key files on the computer that you want access to and they encrypt them and lock them and say 'unless you give us money, you're not getting these files back' and they might be really important files"
"Grab an external hard drive, back up all your important files from your computer and if these guys do get into your computer [at least] you've got these files backed up somewhere and you can get access to them."
One victim of the attack is the UK health system - several operations had to be cancelled because surgeons and doctors couldn't access patient records.
Another Aussie techspert Trevor Long says just how big this attack has been in Australia still isn't known.
"We won't know that for the next 5-6 hours. As people turn on their computers today at work, it's going to affect people"
"Workplaces are the most at risk."
"There are hundreds of mums and dads around Australia, let alone the world, infected right now but it's a little bit less risky for you and I to lose access to our computer cos we'll just wipe it and start again, but a business losing access to their computer.. their files, their back ups, their accounting software.. is hugely crippling."
"I would be very worried if I was a major executive of a company that was running computers that haven't been updated."
As for whether WE are going to be impacted - what exactly are we looking out for?
"Don't click that link is the most important thing," says Trevor.
"That link could be anything from an email that looks like it's from the bank, looks like it's from Australia Post or any organisation. If you click a link in an email that's when you come unstuck,"
"If you think you need to click that link, go to their website first and then log in. The link is the killer. It's not the bank, it's not Australia Post, it's the link that infects you."