National Australia Bank hit by DDoS attack

The National Australia Bank (NAB) has warned its customers to beware of new phishing attacks after the bank's Web site was hit by a DDoS attack earlier this week.

NAB customers experienced problems accessing the online banking service on Wednesday, according to a bank spokesperson.

"We first noticed [the attack] on Wednesday. For the moment it is not having any impact and has been OK for the past 24 hours but there was a bit of residual impact yesterday.

"Customers were having to, in some cases, try a number of times. It did slow down the access and jam the system intermittently," the spokesperson told ZDNet Australia.

According to the spokesperson, the bank decided to re-issue its phishing warning in case the fraudsters use future attacks to try and trick customers into visiting spoofed versions of the bank's Web site.

"That was something that crossed our minds so we thought it would be timely to put out a warning to people -- which we have done before," the spokesperson added.

NAB's CIO, Michelle Tredenick, said in a statement that "Any NAB customer who receives [a phishing] e-mail is advised to delete it without clicking on any embedded links."

Tredenick said that customer's details had not been compromised by the attack: "Customer information has not been at risk as a result of this issue and our security systems have protected our internal systems. But the incident highlighted the need for banks and customers to be vigilant at all times".

Last month, NAB customers received a batch of phishing e-mails that tried to trick them into running a malicious file that had been placed on a hacked Web server run by Sarajevo Airport.

The e-mail contained a number of NAB logos and asks recipients to "renew services" on their account by clicking on a link within the message.