The Realstatistics malware campaign that was discovered in June to be infecting thousands of Joomla! websites was able to quickly gain steam by shifting infection tactics, after an earlier vulnerability workaround closed off its original attack method. The malware campaign now focuses on an exploit vector that has yet to be publicly disclosed.
According to a blog post by Sucuri, Realstatistics' point of infection for websites built on the Joomla! content management system is a remote command execution vulnerability that was detected in December 2015. The original exploit for this flaw involved object injection via the HTTP user agent, resulting in remote code execution. In reaction, the Joomla team created a patch, but also offered a way to block this specific attack through web application firewall ModSecurity rules.
Joomla! website hosts that applied the patch are safe, but those that only employed the workaround are now susceptible to a new malware variation that instead targets the old vulnerability via a second, undisclosed exploit technique that installs a backdoor via the filter-search option. The result: a sudden surge in infection rates as malicious payloads are delivered through the backdoor.
"The recommended protection mechanisms did not block it and it was not mentioned anywhere until now. So the outdated sites that had it covered via ModSecurity rules got compromised," Daniel Cid, Sucuri Founder and CTO, said in a statement emailed to SCMagazine.com