Millions of WordPress sites accepted attack this week, said Defiant, the company behind the Wordfence firewall.
The sudden rise in attacks occurred when hackers discovered and began exploiting a 0day vulnerability in “File Manager, A WordPress plugin used on more than 700.000 websites.
0day allowed an attacker to maliciously upload archives on a site that was running an older version of File Manager.
It is not known how they discovered 0day, but all last week the hackers started looking for sites that had this add-on installed.
If detection was successful, attackers would exploit 0day and upload a web shell disguised as a file image on the victim's server. So they could access the site, adding it to a botnet.
The attacks started late, but intensified throughout the past week. Defiant detected attacks on 1 million WordPress sites as of Friday, September 4th.
In all, Defiant has blocked attacks on more than 1,7 million websites since September 1, when the attacks were first discovered.
The good news is that the File Manager development team created and released an update for 0day the same day they learned of the attacks. Some administrators directly installed the information, but as usual, there are others who didn't.
