If you've been cancelling those annoying little messages telling you to renew your anti-virus software, you might want to think again.
Our "honeypot" suffered serious attack every hour
The average home computer comes under attack from the internet once every twelve minutes.
That's the finding of an experiment by BBC News interactive's Technology team
They set up a "honeypot" computer and connected it to the internet. On its worst night, the PC was attacked 53 times - by worms, spyware and phishing attempts.
This morning on Breakfast:
We talked to one of the team who conducted the experiment, Darren Waters. He's the technology editor of BBC News Interactive.
On one of its worst nights, the PC recorded 11 attacks by a Blaster worm, three attacks from a Slammer worm and one attempt to hijack it completely by subverting the web server built into Microsoft windows.
Basic Safety: top tips
Do: install anti-virus software and keep it up to date
Do: install a personal firewall
Do: use updates from Microsoft or Apple
Don't: open suspicious e-mails
Don't: click on unexpected attachments
Don't: click on links to banks in e-mails
The BBC's honeypot computer was equipped with special software which monitored attempts to attack it.
The computer also received 36 fake security announcements and adverts.
On average, it was hit by a potentially crippling bug once every hour during the experiment.
It's thought there could be around 200,000 malicious computer programmes on the net.
The vast majority of attacks are directed at home computer users, according to the security software firm Symantec.