Australian businesses, either small or large corporations, really ought to ensure they have a good and solid IT system in place, or otherwise always end in the mercy of hackers.

This as the Miami Family Medical Centre on the Gold Coast became the latest of Australian institutions held victim by a group of security hackers. The hackers, believed to be based in Russia, have demanded $4,000 in exchange for the precious files of the medical centre.

Nigel Phair, IT security expert, said the string of Australian businesses being hacked, at five to ten a week, should already be enough of a "wake-up call."

"Cyber criminals based mainly throughout Eastern Europe look for rich targets, places with identifying information to extort," Mr Phair, director of the Centre for Internet Safety and a former investigator with the Australian High-Tech Crime Centre, told ABC News.

As with most businesses, David Wood, Miami Family Medical Centre's co-owner, thought his centre's IT system was good and solid.

"We've got all the anti-virus stuff in place - there's no sign of a virus. They literally got in, hijacked the server and then ran their encryption software," he told ABC News.

"It's people who know how to break in past firewalls and hack passwords to get onto the server," he added.

But Mr Wood assured patients of the Miami Family Medical Centre that no data was stolen. "It's secure in the sense that no-one's taken any of it."

"We had taken offline the server that had been targeted while thinking what to do with it," Mr Wood said.

But Mr Wood admitted the centre is currently having a difficult time checking on patients with no medical records on hand.

"That's seven years worth of data missing or gone. They have hacked us really well because they've been in and disabled quite a number of programs. They've corrupted all our back-up discs too."

For hackers, among their biggest targets, according to Mr Phair, are health professions since they store valuable information as well as collect credit card details.