Managed.com said the incident only impacted a limited number of customer sites, which the company said it immediately took offline.
But hours after the attack, Managed.com said it also took down its entire web hosting infrastructure, which the company is now working to restore.
This included WordPress and DotNetNuke managed hosting solutions, email servers, DNS servers, RDP access points, FTP servers, and online databases.
Initially, the company passed the attack as unscheduled maintenance but eventually came clean in emails and messages provided by its tech support operators to an ever-increasing number of angry customers.
The company says it is now working with law enforcement to identify the attackers and restore customer systems as soon as possible.
But on online forums, Managed.com customers now fear that their sites will remain down for days or weeks. They cite a similar incident that took place at fellow web hosting provider A2 Hosting in May 2019, from which the company needed more than a month to recover, during which time a large number of customers had to wait for their sites and site data to be restored.
A Managed.com spokesperson did not return a request for comment before this article's publication.