More than 160,000 Wordpress blogs have been used to perform Distributed Denial of Service (DDoS) attacks against other websites.
The Wordpress sites were used to perform the attacks if they had pingbacks or trackbacks enabled, which is activated by default when a new blog is set up.
The problem was revealed when one site went down because it was getting too many access requests. Quickly, it was closed down by its host for overloading the server.
The website owner then contacted Securi Research to halt the attacks.
Sucuri CTO and OSSEC founder Daniel Cid said in a blog post: "Once the DNS was ported we were able to see what was going on, it was a large HTTP-based (layer 7) distributed flood attack, sending hundreds of requests per second to their server.
"All queries had a random value (like "?4137049=643182?) that bypassed their cache and force a full page reload every single time," Cid said.
The company discovered all the requests were coming from legitimate and non-harmful Wordpress sites sending random requests via a ping back request to the XML-RPC file, which quickly overloaded the server.
Cid also explained in the post that Wordpress site owners can stop their site being involved in future attacks by inserting the code below into their Wordpress site:
add_filter( xmlrpc_methods', function( $methods ) { unset( $methods['pingback.ping'] ); return $methods; } );
Anyone who suspects their site may have been used in an attack can check its url against the logs on Securi's website.
Last month, web hosting firm CloudFlare was subject to a DDoS attack that was so large it slowed down European and US networks for more than 24 hours.
CloudFlare CEO Matthew Prince said via Twitter it was larger than the one suffered by anti-spam group Spamhaus last year and warned, Someone's got a big, new cannon. Start of ugly things to come.'
-
RSAC Conference 2025: The front line of cyber innovationITPro Podcast Ransomware, quantum computing, and an unsurprising focus on AI were highlights of this year's event
-
Anthropic CEO Dario Amodei thinks we're burying our heads in the sand on AI job lossesNews With AI set to hit entry-level jobs especially, some industry execs say clear warning signs are being ignored
-
UK crime fighters wrangle “several thousand” potential cyber criminals in DDoS-for-hire honeypotNews The sting follows a recent crackdown on DDoS-for-hire services globally
-
US begins seizure of 48 DDoS-for-hire services following global investigationNews Six people have been arrested who allegedly oversaw computer attacks launched using booters
-
Will triple extortion ransomware truly take off?In-depth Operators are now launching attacks with three extortion layers, but there are limitations to this model
-
GoDaddy web hosting reviewReviews GoDaddy web hosting is backed by competitive prices and a beginner-friendly dashboard, and while popular, beware of hidden prices
-
Japan investigates potential Russian Killnet cyber attacksNews The hacker group has said it’s revolting against the country’s militarism and that it’s “kicking the samurai”
-
LockBit hacking group to be 'more aggressive' after falling victim to large-scale DDoS attackNews The ransomware group is currently embroiled in a battle after it leaked data belonging to cyber security company Entrust
-
Record for the largest ever HTTPS DDoS attack smashed once againNews The DDoS attack lasted 69 minutes and surpassed the previous record of 26 million RPS
-
Cloudflare mitigates biggest ever HTTPS DDoS attackNews A botnet generated over 212 million HTTPS requests from over 1,500 networks in 121 countries
