Geneva - Swiss bank BCGE said on Thursday hackers had stolen the personal data of thousands of clients as a newspaper reported it was being blackmailed.
The Banque Cantonale de Geneve said the theft had affected several thousand of its estimated 240 000 clients, but that there had been "no financial damage".
The hackers, calling themselves Rex Mundi, were threatening to publish some 30 000 emails of the affected clients if the bank did not hand over 10 000 euros (R138 490) by Friday, the Le Temps daily reported.
The threat was reportedly made on Twitter.
According to Cyber War Zone the Rex Mundi hacking team is currently also allowing new people to join the hacking team as well as those who wanted to grant Bitcoins to the hackers. "The Rex Mundi hackers have been active for a couple of years and they have been able to stay out of the hands of any government agencies,
The cantonal bank, which focuses on small and medium-sized businesses and on portfolio investments, refused to comment on the blackmail report when contacted by AFP.
BCGE said the authorities have launched an investigation into the hacking.
The stolen data included names, addresses, telephone numbers and account numbers.
The bank said it had beefed up internet security and blocked access to online forms.
Reminder: The Banque Cantonale de Geneve has until tomorrow to pay us and prevent customer data from getting leaked. http://t.co/uTdLLeL2O1
— Rex Mundi (@rexmundi14) January 8, 2015