While investigating a compromised site we discovered some suspicious code in a theme by AccessPress Themes (aka Access Keys), a vendor with a large number of popular themes and plugins. On further investigation, we found that all the themes and most plugins from the vendor contained this suspicious code, but only if downloaded from their own website. The same extensions were fine if downloaded or installed directly from the WordPress.org directory.
Due to the way the extensions were compromised, we suspected an external attacker had breached the website of AccessPress Themes in an attempt to use their extensions to infect further sites.
We contacted the vendor immediately, but at first we did not receive a response. After escalating it to the WordPress.org plugin team, our suspicions were confirmed. AccessPress Themes websites were breached in the first half of September 2021, and the extensions available for download on their site were injected with a backdoor.
Once we had established a channel for communicating with the vendor, we shared our detailed findings with them. They immediately removed the offending extensions from their website.
Most of the plugins have since been updated, and known clean versions are listed towards the bottom of this post. However, the affected themes have not been updated, and are pulled from the WordPress.org theme repository. If you have any of the themes listed towards the bottom of this post installed on your site, we recommend migrating to a new theme as soon as possible.
This disclosure concerns a large number of extensions, both plugins and themes. Skip to the list below, or read on for the details.
Continue reading → Backdoor Found in Themes and Plugins from AccessPress Themes