Overview Back in early December we announced our “no browser left behind” initiative to the world. Since then, we have served well over 500 billion SHA-1 certificates to visitors that otherwise would not have been able to communicate securely with our customers’ sites using HTTPS. All the while, we’ve continued to present newer SHA-2 certificates […]
Archive | Security
RSS feed for this sectionServer Security: Indicators of Compromised Behavior with OSSEC
We leverage OSSEC extensively here at Sucuri to help monitor and protect our servers. If you are not familiar with OSSEC, it is an open source Intrusion Detection System (HIDS); it has a powerful correlation and analysis engine that integrates log analysis, file integrity monitoring, rootkit detection, real-time alerting, and active response. It provides complete coverageRead […]
When a WordPress Plugin Goes Bad
Last summer we shared a story about the SweetCaptcha WordPress plugin injecting ads and causing malvertising problems for websites that leveraged the plugin. When this plugin was removed from the official WordPress Plugin directory, the authors revived another WordPress account with a long abandoned plugin and uploaded SweetCaptcha as a “new version” of that plugin. InRead […]
A Deep Dive Into DNS Packet Sizes: Why Smaller Packet Sizes Keep The Internet Safe
Yesterday we wrote about the 400 gigabit per second attacks we see on our network. One way that attackers DDoS websites is by repeatedly doing DNS lookups that have small queries, but large answers. The attackers spoof their IP address so that the DNS answers are sent to the server they are attacking, this is […]
A tale of a DNS exploit: CVE-2015-7547
This post was written by Marek Vavruša and Jaime Cochran, who found out they were both independently working on the same glibc vulnerability attack vectors at 3am last Tuesday. A buffer overflow error in GNU libc DNS stub resolver code was announced last week as CVE-2015-7547. While it doesn’t have any nickname yet (last year’s […]
Behind the Malware – Botnet Analysis
While analyzing our website firewall logs we discovered an old vulnerability in the RevSlider plugin being retargeted. RevSlider, the plugin whose vulnerability led to massive website compromises in 2015, was being leveraged again in an attempt to infect websites over a year since its initial disclosure. The original hack required sending an AJAX request containing the action revslider_ajax_action toRead […]
Introducing CloudFlare Registrar: Designed for Security, Not the Masses
At CloudFlare, we’ve constructed one of the world’s largest networks purpose-built to protect our customers from a wide range of attacks. We’re so good at it that attackers increasingly look for ways to go around us, rather than go through us. One of the biggest risks for high-profile customers has been having their domain stolen […]
Investigating a Compromised Server with Rootcheck
What do you do if you suspect your server (VPS or dedicated) has been compromised? If you are a customer, you have the option to leverage our team to perform the incident response on your behalf, but what if you want to do an investigation on your own? In this post, we will talk aboutRead […]
We’re hosting a Null Singapore meetup!
We’re happy to announce that next week CloudFlare is hosting the Null Security meetup in Singapore. You are invited! Null is a community for hackers and security enthusiasts. Monthly meetups are organized in a number of Asian cities. Read more at http://null.co.in/. The lineup for the February meetup: All you ever wanted to know about […]
WordPress Sites Leveraged in Layer 7 DDoS Campaigns
We first disclosed that the WordPress pingback method was being misused to perform massive layer 7 Distributed Denial of Service (DDoS) attacks back on March 2014. The problem, as previously described,was that any WordPress website with the pingback feature enabled (which is on by default) could be used to attack the availability of other websites. The attacks wouldRead […]
