The company is working to get their systems up and running again in time for today's scheduled sales in Sydney, Melbourne and Fremantle.

Executive director of the National Council of Wool Selling Brokers of Australia, Chris Wilcox, said if the system wasn't fully operational by 2pm today's sales would also have to be deferred.

The Sydney sales were due to start at 11am today.

Talman has been providing IT systems to the Australian and NZ wool industries since 1976.

More than 75 per cent of the wool industry in Australia and NZ uses Talman software for tasks such as collation of test data, sale cataloguing and valuations.

Ransomware is a type of malware that holds data for ransom and has been around for many years.

Attacks shot up in the middle of the 2010s to crisis levels but the ransomware boom seemed to have been petering out in recent times.

More to come