SiteGround CDN under attack mode security for websites

Block Sophisticated HTTP Attacks with SiteGround CDN's 'Under Attack' Mode

As a leading provider of web hosting services, at SiteGround we continually strive to offer the most advanced and reliable solutions to our customers, with a strong focus on website security. In our latest Website Horror Stories series for #cybersecuritymonth, we even gathered real stories of webmasters who suffered some kind of website attack or hack, which could have easily been avoided with our suite of website security services. Now we’re excited to announce a new feature addition to our security features – ‘Under Attack Mode’, part of SiteGround in-house CDN.

Our hosting services already encompass robust network attack protection. Our Distributed Denial of Service (DDoS) protection effectively blocks a significant percentage of malicious traffic, ensuring your websites remain accessible and secure. But despite the effectiveness of all our website protection systems and security features, some HTTP attacks are more sophisticated and can circumvent traditional solutions. To further fortify your website’s defenses against these advanced threats, we’ve developed the new ‘Under Attack Mode’ feature, now part of our SiteGround CDN service.

Understanding SiteGround’s ‘Under Attack Mode’

SiteGround CDN’s ‘Under Attack Mode’ adds an additional layer of protection against potentially malicious HTTP traffic. If your website is under an HTTP attack, it’s immediately overloaded with fake traffic requests, usually coming from malicious bots, which makes it inaccessible for real users. 

When turned on, our Under Attack feature challenges website visits with an automatic CAPTCHA, verifying that they are humans and not bots. It leverages JavaScript to perform automated mathematical calculations in the visitor’s browser. While these calculations are being processed, the end visitors see a loading message for a few seconds. Once the challenge is solved, indicating the visitor is most likely a real human, the system automatically redirects them to the website. This means your website will remain accessible to your real users even if it’s under attack – legitimate traffic will be allowed to proceed to your site, while we block the fake bot traffic.

How to Enable Under Attack Mode

Our ‘Under Attack Mode’ is available as part of our Premium CDN plan. If you’re looking for a way to further enhance the security of your website against sophisticated HTTP attacks, our paid plan now offers this advanced feature, together with a myriad of speed and security enhancements.

Once you’re using SiteGround CDN’s Premium plan, enabling the ‘Under Attack Mode’ is simple. It can be activated per domain name from the Site Tools management interface. Once enabled, the ‘Under Attack’ mode feature operates for a period of 24 hours, after which it is automatically disabled by the system.

Please note that while ‘Under Attack Mode’ is enabled, some third-party website analytics tools may not function correctly, as they may not be able to pass the challenge. This is why the feature is automatically disabled after 24 hours – to prevent any prolonged disruption to your website analytics.

SiteGround CDN’s ‘Under Attack Mode’ applies to all website visitors and all traffic towards the domain. This means all requests – from real users, bots, to API requests from third-party systems – are challenged, ensuring comprehensive protection.


Our latest SiteGround CDN security feature, the ‘Under Attack Mode’ is a testament to SiteGround’s commitment to providing superior security for our users. We understand the evolving nature of web threats and continually innovate to offer features that keep your website safe and accessible. Stay ahead of the curve with SiteGround CDN’s ‘Under Attack Mode’.

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author avatar

Daniel Kanchev

Director Product Development

Daniel is responsible for bringing new products to life at SiteGround. This involves handling all types of tasks and communication across multiple teams. Enthusiastic about technology, user experience, security and performance, you can never be bored hanging around him. Also an occasional conference speaker and travel addict.


Comments ( 2 )

author avatar


Oct 26, 2023

Hello, I want to buy siteground hosting service but unable to talk to the support to select a right plan for me. I ant shared hosting plan for my website their disk space is more than 100GB. i can't find the plan with that much memory. And Contact Us section only allows register user to chat with support team.

author avatar

Gabriela Andonova Siteground Team

Oct 26, 2023

Hello Fatima! Thank you for your interest in our services. While our shared hosting options offer 10GB to 40GB of disk space, our Cloud hosting plans are designed to provide flexible resources to meet your specific requirements. Our sales team is readily available to address any inquiries you might have regarding our plans and to assist you in selecting the most suitable option for your needs. Feel free to reach out to them through our 24/7 live chat at your convenience!


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