Website Security News

Vulnerability reports and responsible disclosures are essential for website security awareness and education. Automated attacks targeting known software vulnerabilities are one of the leading causes of website compromises. To help educate website owners about potential threats to their environments, we’ve compiled a list of important security updates and vulnerability patches for the WordPress ecosystem this past month. The vulnerabilities listed below are virtually patched by the Sucuri Firewall and existing clients are protected. Continue reading Vulnerability & Patch Roundup — October 2025 at Sucuri Blog.

If your website suddenly crawls to a halt, pages time out, or customers report they can’t log in, you might be staring down a Denial-of-Service (DoS) attack. These incidents don’t require exotic zero-days or deep levels of access. More often, they’re brutally simple: overwhelm the target with traffic or requests until legitimate users can’t get through. For online businesses, the end result is the same: lost revenue, support tickets piling up, and shaken trust. Below we’ll go over some DoS basics: what a DoS attack is, how it differs from distributed variants (DDoS), what happens under the hood, common techniques, the warning signs, and practical steps to reduce your risk and respond effectively. Continue reading Denial-of-Service (DoS) Attacks: What They Are, How They Work, and How to Defend Your Site at Sucuri Blog.

How a simple “Send a copy to yourself” feature led to 149,700 spam emails and what you can do to prevent it The Emergency Call It started like many server emergencies do – with a panicked message about massive server performance issues. A client’s website was grinding to a halt, CPU usage was through the roof, and something called dovecot/lmtp was consuming enormous resources. But this wasn’t just a performance problem – it was the beginning of uncovering a sophisticated spam operation hiding in plain sight. Continue reading Contact Form Spam Attack: An Innocent Feature Caused a Massive Problem at Sucuri Blog.

When a website fails, your browser returns an HTTP status code that’s short, technical, and often cryptic. You’ve probably seen 404 Not Found or 500 Internal Server Error. Less common, but just as disruptive, is 501 Not Implemented. This guide explains what a 501 error actually means, how it presents in browsers, what typically causes it, how it can affect user trust and SEO, and the most effective, platform‑agnostic steps to resolve it. Continue reading What Is a 501 Error & How to Fix It at Sucuri Blog.

Learn. Secure. Lead. We’re excited to introduce the beta launch of Sucuri Academy—a cutting-edge learning platform designed to empower website owners, developers, and digital professionals with the skills to defend against cyber threats. Whether you’re just starting out or looking to master advanced security techniques, Sucuri Academy offers structured, expert-led courses to help you protect your digital assets with confidence. Why Sucuri Academy? In today’s digital landscape, website security is no longer optional, it’s essential. Continue reading Introducing Sucuri Academy: Your New Destination for Website Security Education at Sucuri Blog.

Recently, one of our customers noticed suspicious JavaScript loading across their WordPress website. Visitors were being served third-party scripts that the site owner never installed. After investigation, we discovered the infection originated from a malicious modification in the active theme’s functions.php file. This injected PHP code silently fetched external JavaScript from attacker-controlled domains and inserted it into the site’s front-end. Behind the Breach We found a suspicious script loading on the client’s website. Continue reading Malvertising Campaign Hides in Plain Sight on WordPress Websites at Sucuri Blog.

Vulnerability reports and responsible disclosures are essential for website security awareness and education. Automated attacks targeting known software vulnerabilities are one of the leading causes of website compromises. To help educate website owners about potential threats to their environments, we’ve compiled a list of important security updates and vulnerability patches for the WordPress ecosystem this past month. The vulnerabilities listed below are virtually patched by the Sucuri Firewall and existing clients are protected. Continue reading Vulnerability & Patch Roundup — September 2025 at Sucuri Blog.

Attackers scan for TCP 22 and 2222 around the clock. When they find an open port, they launch credential-stuffing lists harvested from previous leaks, brute-force scripts, and even malware that hunts for hard-coded passwords in deployment repositories. Verizon’s 2025 Data Breach Investigations Report (DBIR) continues to show stolen credentials as a leading initial access vector because many organizations still rely on simple passwords for SSH and SFTP. Once an outsider lands shell access or write permission to an upload directory, web-facing code and client data follow quickly. Continue reading Enhancing File Transfer Security with SSH Key Authentication at Sucuri Blog.

Navigating to your WordPress site only to be met with the White Screen of Death (WSoD) can be a daunting experience. This error denies access to your site for both administrators and visitors, disrupting your website’s performance and user experience. Despite its prevalence, this common WordPress problem has a number of straightforward solutions. In this post, we’ll cover what the WordPress white screen error is, outline the most common reasons for this issue, and detail the steps you can take to resolve it. Continue reading Troubleshooting WordPress: How to Fix the White Screen of Death (WSoD) at Sucuri Blog.

During a recent cleanup of a compromised WordPress website, we discovered two different malicious files designed to silently manipulate administrator accounts. Attackers often inject such backdoors to maintain persistent access to a site, even if their other malware is detected and removed. These files were disguised to look like regular WordPress components, but their functionality told a different story. What did we find? We found two highly suspicious files that immediately caught our attention. Continue reading Hidden WordPress Backdoors Creating Admin Accounts at Sucuri Blog.

In an era when email remains one of the most important forms of communication for business, commerce, and personal use, ensuring that emails reach their intended recipients (and don’t end up in spam, or worse, aiding cybercrime) is more important than ever. One of the often “behind‐the‐scenes” organizations helping to defend email systems is Spamhaus. In this post, we’ll explain what Spamhaus is, how it works, why it matters, and what best practices companies should follow to stay out of blacklists and protect deliverability. Continue reading Understanding Spamhaus and Its Role in Email Security at Sucuri Blog.