eResources founding director Rod Brugman said the majority of attacks were introduced to business computer systems by staff clicking on inviting emails through hyperlinks.

He said in his experience it was unusual for businesses to pay ransomware demands, but it took a lot of time and effort to retrieve data.

"It's pretty serious. In the past three years cyber attacks have had a massive impact on Warrnambool business and some are fairly big business," he said.

"It's often that tempting email hyperlink that gets hold of your system. Local businesses are experiencing these things (and) either pay the money or they have to try and restore the data."

Cyber security is topical after hospitals across the south-west were the focus of a ransomware attack last week which has left staff without internet access or emails and is still having a significant impact.

In the past two years Warrnambool businesses have also been targeted in bank account-changing email scams.

Emmanuel College lost all but $1200 of a $480,000 transaction mid last year while The Midfield Group and Wannon Water have also been subject of similar scams.

Mr Brugman said cyber attacks were often via a tempting email.

"It could be an email purporting to be from Australia Post, saying click here on a hyperlink about a parcel which then introduces the virus," he said.

"We've seen this the last two or three years. It's taken a number of local businesses down totally. It's pretty serious stuff once it gets in.

"As an IT business we've had to restore data 50 or 60 times. We've seen some email scams, but that's basically an identity theft where someone gets details, monitors emails and then recreates what looks like legitimate documents.

"The outcome is the same, it's extortion. It's more difficult to get those email details, it takes concentrated effort to create those documents."

Mr Brugman said malware was a more blanket approach.

"These problems are not going away. It's a very easy mistake, to click on something that looks completely normal," he said.

"The ransom demands can be from hundreds up to thousands of dollars.

"The data is gone basically. The files are encrypted and not usable."

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The IT chief said viruses a couple of years ago were more primitive and restricted to images or spread sheets but now advanced databases were susceptible.

"We're talking about full system restores. It pretty much only happens to Microsoft systems," he said.

"There's massive amounts of work to retrieve that data in a full system restore. Small customers often don't have back-up systems and with bigger companies a full restore can take days.

"People are talking about cyber attacks but they are not quite getting the point. These emails are tempting and if you drop your guard and click on something you shouldn't, you can very easily get caught."

Mr Brugman said businesses were now investing more in training staff.

"You have to try and overcome that human weakness. If someone clicked on the wrong thing it can have a massive impact. We can all be weak and susceptible," he said.

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