Telstra boss Andy Penn has warned the shift to working from home gives cyber criminals greater opportunity to steal data and employers must improve their defences.
Mr Penn, chair of an industry committee on cyber security, said the many people working from home due to the pandemic meant lots of data was no longer protected by corporate networks.
The risks do not only apply to big business.
"Private and public sector organisations of all sizes handle data that cyber criminals would love to get their hands on," Mr Penn told an information security conference on Wednesday.
"And with hybrid working that data is now in a potentially more vulnerable environment."
Workers using home internet services and unsecured networks at cafes were at risk, Mr Penn said.
Cyber criminals had evolved to become nation-states which sponsored attacks, and businesses selling hacking toolkits, he said.
"The world is waking up to the reality that cybercrime is no longer a cottage industry. It's big business," Mr Penn said.
The cyber security industry advisory committee has published a report advising how to protect the increasingly remote and mobile workforce.
The report encourages practical measures to protect systems from threats. These include ensuring software is regularly updated, networks are secured for people bringing devices from home, systems are regularly backed-up and there are multiple forms of identity checks.
In September, the annual cyber threat report revealed more than 67,500 cybercrimes in the 2020-21 financial year. This was an increase of 13 per cent from the year before.
Logistics company Toll Holdings is among those to have recently been targeted by cyber attackers.
Nine Entertainment earlier this year struggled to televise nightly bulletins and produce newspapers due to cyber attack.