A cyber attack caused HSBC's online banking to crash for the second time in a month

HSBC's online banking facility has gone down for the second time in less than a month, after the bank was hit by a cyber attack.

A statement given to the BBC by HSBC said:

"HSBC internet banking came under a denial of service attack this morning, which affected personal banking websites in the UK."

"HSBC has successfully defended against the attack, and customer transactions were not affected. We are working hard to restore services, and normal service is now being resumed.

Customers currently trying to log onto HSBC's site are met with a message saying:

"We'd like to apologise to all our customers for Online Banking being unavailable. We know how inconvenient this is and we are doing everything we can to rectify the problem. Please try later."

The bank says it was hit by a denial of service, also known as a DDoS, attack. This method of attack basically floods a website with traffic from multiple systems, overloading servers and causing the site to crash. It is the same method used against the BBC website on New Year's Eve.

This is the second time in just over three weeks that HSBC's online systems have gone down. On January 4th, HSBC's internet banking service went down for the first time, in an outage that spread across two days. The crash led to Britain's banking regulator, the Financial Conductor Authority, to scrutinise HSBC.

At the time a spokesperson told Business Insider: "The FCA is in contact with HSBC regarding a recent IT issue. We will be working closely with the bank as it resolves the problem and to ensure there are steps in place to help consumers who are affected."

After the previous outage, HSBC promised to waive all charges incurred by customers when services were down.

In 2014, the Royal Bank of Scotland, Natwest and Ulster Bank were fined a combined £42 million for IT failures which occurred in June 2012 and meant that the banks' customers could not access banking services.

Business Insider has contacted HSBC, and will update this story when we hear back.