Billions of people use the internet every day and, more often than not, unknowingly and unwillingly download dangerous software onto their computers.

But programmers at the Google offices in Montreal are doing their part to keep the web safe.

Fabrice Jaubert, Nav Jagpal and Robert Shield track down websites that are harmful in order to protect people from malicious content online.

"It's challenging but our team works really hard to protect users by building technology into browsers, into search engines to make it hard for these guys to take advantage of users online," said Jagpal.

Along with their fight against malware and phishing scams their larger target is something they've nicknamed 'ooze.'

"We were getting a lot of user complaints that people were finding that their computers were misbehaving, slow, not producing the results they were expecting," said Jaubert.

The culprit: software that users were not aware they had downloaded.

Those trying to illegally download movies or music are most likely to get malware, but mainstream users are also vulnerable.

"Regardless of what you do on the web at some point someone will want to download a utility which is perfectly legitimate but it'll often come bundled with ooze," said Jaubert.

So how do you know that your machine has it?

"When I try to open up a website all of a sudden the website looks different, things start to pop up. And if you wait a second or two [you realize] this isn't what I wanted and now I'm told I have an error or a system error. When I try to click through I get more and more aggressive pop ups," said Shield.

The malware often forces users to give up their computers and buy a new one.

"So how did this happen? I just wasn't careful. I just clicked 'yes, download' and didn't pay attention to the warnings," said Shield.

Those warnings are created by Google to help the public, and each week at least 60 million warnings are generated.

The battle is far from over, but Shield and the other developers are trying to stay ahead of the game.

"There's new stuff that comes up every day. It's really like an arms race," said Shield.

But it's a race that Google knows it cannot win on its own unless computer users remember to be vigilant.