The attack, which was first detected at 6am, saw the blocking of access
to the NAB’s site and slow log-ons for the bank’s internet banking
customers occured intermittently throughout the day, NAB spokesperson
Megan Lane said.

Thus
far, the NAB was not aware of the source or motivation of the attack,
Lane said, but the event had been referred to the Australian High Tech
Crime Centre (AHTCC) – a section of the Australian Federal Police.

The
incident was not the first time the NAB had been targeted by a DoS
attack, she said, but this instance was one of the “more significant”
efforts to block access to the company’s website.

AFP spokesperson Nicholas Pedley confirmed that a referral from the NAB
had been received and said the AFP was investigating this matter.

“The
AFP takes any activity of this nature seriously and is working closely
with the NAB to resolve the matter as quickly as possible,” he said.

In announcing the DoS attack, the NAB has renewed its campaign warning of the dangers of hoax emails, Lane said.

However,
the bank was uncertain as to whether the DoS attack was being used as a
pretext to soften up customers for a phishing attack through creating
the expectation of special emails from the bank explaining the
interruptions to the website.

“We just think it’s timely to remind customers that we will never ask them for their details,” she said.