Speaking at the e-Crime Congress in London, Alan Jebson, HSBC's group chief operating officer, said that the bank often received tens of thousands times that figure.
"I was interested to hear it was seven attacks a day," Jebson said. "On our worst day last year, we had 100,000 attacks."
The British technology police, the National Hi-Tech Crime Unit, said Monday that U.K. companies receive an average of seven viruses a day.
HSBC holds more than a trillion dollars in assets, making it a tempting target for virus writers and hackers. But e-mail identity theft scams are posing a greater threat to the bank's 18.9 million online customers, Jebson said.
"We are naturally very concerned about anything that would damage online banking," Jebson said. "Customers will only do business online if they are convinced it is secure. Customers are no longer sure whether e-mails from financial institutions are genuine."
typically use e-mails that appear to come from trusted providers such as banks or online retailers. The e-mails contain links to fake Web sites that seem to belong to those companies, but that are actually hosted by the fraudsters, who hope to lure victims into handing over confidential information such as passwords and credit card numbers.
"There is evidence that frauds are damaging consumer confidence," Jebson noted. "Research has shown that the take-up of (e-commerce) is slowing."
Jebson emphasized thatand customers need to cooperate in their efforts to thwart scammers. He said that HSBC is cooperating with the likes of Citibank to share information on security, and the bank is even considering the use of biometrics in three-factor authentication--where a customer would need to supply three different pieces of information to prove identity.
"The harder we make it for criminals to access accounts, the harder we make it for the public. But this is a game we cannot afford to lose," Jebson said.
Dan Ilett of ZDNet UK reported from London.