Security News > 2022 > July > Attackers scan 1.6 million WordPress sites for vulnerable plugin
Security researchers have detected a massive campaign that scanned close to 1.6 million WordPress sites for the presence of a vulnerable plugin that allows uploading files without authentication.
The vulnerability would allow an unauthenticated attacker to inject malicious Javascript to sites using any version of the plugin and perform actions like uploading and deleting files, which could lead to complete takeover of the site.
While the size of the campaign is impressive, with 1,599,852 unique sites being targeted, only a small portion of them are running the vulnerable plugin.
Researchers at Defiant, the maker of the Wordfence security solution for WordPress, observed an average of almost half a million attack attempts per day against customer sites they protect.
The attackers send a POST request to 'wp-admin/admin-ajax/php', attempting to use the plugin's 'uploadFontIcon' AJAX function to upload a malicious ZIP payload that contains a PHP file.
This file, in turn, fetches the NDSW trojan, which injects code in legitimate Javascript files present on the target sites to redirect visitors to malicious destinations like phishing and malware-dropping sites.