Lloyds Banking Group is understood to have been the target of a significant denial of service attack earlier this month, leaving significant numbers of customers unable to access their online banking services.
The attack started at some point on the morning of January 11, preventing customer access to sites belonging to group members including Lloyds Bank, Halifax, and the Bank of Scotland for at least the best part of three days.
Little was made of the attack at the time, but the Financial Times now reports that Lloyds Group is working with the National Cyber Security Centre to find the source of the attack.
No one has claimed responsibility for the DDoS, and if Lloyds—which is Britain’s largest mortgage lender—knows exactly how many customers were affected, it’s not saying.
A spokesperson for Lloyds declined to comment in detail on the nature of the attack, adding it would be “inaccurate to use the word ‘hack.'” He toldthat some of its customers had experienced slow access to its services, before adding:
We experienced intermittent service issues with Internet banking between Wednesday morning and Friday afternoon the week before last and are sorry for any inconvenience caused.
We had a normal service in place for the vast majority of this period and only a small number of customers experienced problems. In most cases if customers attempted another log in they were able to access their accounts.
We will not speculate on the cause of these intermittent issues.
Direct denial of service attacks are a particularly unsophisticated variety of cyberattack. They work by overwhelming a website with too many fake requests for information for it to handle, causing it to slow down for legitimate customers, or altogether crash.
Lloyds isn’t the only bank under the spotlight for suspicious activity on its online service. In November, a hack attack on 9,000 Tesco Bank accounts led to £2.5 million-worth of refunds being paid out to customers who were targeted by fraudsters.
Ars has asked the NCSC for a comment on its investigation.
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