After a week of being bruised and battered over elevated reputation and credit risks , the last thing the bankers attending The Australian Financial Review Banking and Wealth Summit needed was a reminder of the rising operational risks from cyber attacks . But the straight-shooting chief executive of Insurance Australia Group , Peter Harmer , did not dodge the question when asked what his firm had found while trawling through the `` dark web '' . He said IAG had uncovered the personal details of customers belonging to one of the big four banks . The information was being sold online for $ 25 per customer . That suggests the systems of at least one major financial institution have been breached Attack.Databreach and customer data stolen Attack.Databreach . Harmer was primed for this conversation about cyber risks at the Summit . On Wednesday he had led the IAG board of directors on a tour of the company 's cyber-security facility in Sydney . He said any chief executive who believes they have a secure digital environment is `` completely oblivious to the threats that are out there '' . `` We trawl our systems all the time looking for unusual activity , '' he said . `` We trawl the dark net looking for where our data might be up for sale , and it 's amazing when you actually see what is being offered for sale . All we 've found is a couple of our employees ' names and addresses , so our view is that we are reasonably confident with the analysis , and being able to thwart the hackers coming into our system . '' Harmer 's most worrying revelation was that the global capacity for cyber protection was a measly $ 500 million . He said for a business such as IAG , which has a market capitalisation of $ 14 billion , this amount of insurance `` would not even touch the sides '' . This made it imperative for companies to invest in defence efforts and avoid any major extraction of data Attack.Databreach by cyber attackers . On Wednesday , bankers attending the summit were reminded of the lack of trust in the community towards financial institutions .