Unknown assailants are engaging in a high distributed and directed attacks at computers running the WordPress application to commandeer servers. They are using more that 90,000 IP addresses to apply brute force to crack vulnerable WordPress systems and gain administrative credentials for themselves. The reports have been confirmed by three separate web hosting services.
A regular botnet comprises of regular computers that have been taken over. However, with these attacks servers are at risk and being taken over to be added to the botnet setup. Servers generally have access to more more bandwidth than computers intended for personal or business use, making them much more dangerous when included in a farm of infected machines.
According to Cloudflare, the brute force attack being used tries to get into systems by using the username "admin" and then attempting to log in by inputting a list of 100 commonly used password. Those who have WordPress installed are strongly suggested to log in and change their password while ensuring it meets the criteria for good strength.