CUSTOMERS of two of Ireland's largest banks have been targeted by cyber criminals.
Both AIB and Permanent TSB today confirmed that some customers may have fallen victim to fraudulent credit card transactions.
And two other financial institutions – Bank of Ireland and Ulster Bank – say they are closely monitoring customers' accounts as the fallout from the cyber attack continues.
The massive online breach has put several leading companies on alert as gardai continue a major criminal investigation.
AIB and Permanent TSB today said that fraudulent activity took place as a result of the hacking of a customer database at the Irish marketing and travel business Loyaltybuild.
Permanent TSB said that it is getting in touch with customers after fraud was uncovered following a preliminary review.
But the issue is also being closely monitored by other financial institutions – with Ulster Bank today stating that it is examining the issue.
Meanwhile, Bank of Ireland said it is conducting a forensic analysis on credit cards that may have been affected.
As the scale of the crisis continued to escalate, it emerged that 6,700 customers of Electric Ireland were also on the list of credit card users whose details had been compromised.
Overall, it is estimated that the hacking attack exposed either the financial details or personal information of 1.1m people to online raiders.
Some 376,000 people had their credit card details stolen, while a further 150,000 have seen their details potentially compromised.
The cyber attack began with Supervalu but has spread to AXA Insurance, Stena Line, Electric Ireland and potentially a number of banks.
Fianna Fail today called on the financial regulator to intervene.
"We would ask that the financial regulator now get involved in this and bring an end to the information deficit here and give reassurances to people around this issue as well as the data protection agency," said the party's Jobs spokesperson Dara Calleary.
Garda Commissioner Martin Callinan said the likelihood that those behind the hacking were foreign criminals was putting an extra strain on fraud squad detectives.