The consumer banking website of JPMorgan Chase & Co went temporarily offline on Tuesday after hackers targeted it with a denial of service (DoS) attack.
Following the attack, the site's usual banking content and tools were replaced with a message that read, "Our website is temporarily down, but our branches and mobile apps are available." The site has since been restored.
According to NBC News, the hacking group, al-Qassam Cyber Fighters, has taken responsibility for the attack in protest against what it says is a US refusal to remove the YouTube video "Innocence of Muslims", which the group sees as offensive.
DoS attacks are designed to overload servers by flooding them with hundreds of thousands of communication requests in order to disrupt the services they host.
A Ponemon Institute report, published earlier this year found that the websites of almost two-thirds of retail banks in the US, including Citigroup, Bank of America and JP Morgan were targeted with multiple DDoS attacks in 2012. It further urged that banking corporations take all necessary preventative measures as the number of such attacks are likely to increase in the coming months.