100,000 websites were deleted on Sunday evening when hackers exploited a vulnerability found in UK web hosting provider Vaserv.com.
The unknown hackers breached the web host's system by exploiting a vulnerability in a virtualization app.
Vaserv's site shows a lengthy index log of updates from technicians working to recover lost data.
Vaserv director Rus Foster says he has already heard from others that they too have been hit with the same exploit - a zero-day exploit in version 2.0.7992 of the LXLabs-developd HyperVM.
The report on The Register points out that it is still unclear if other web hosts using the HyperVM application have been hit with a similar attack.
Foster says that all the information contained on about half of the company's hosted websites was instantly wiped sometime on Sunday evening following the attack.
About half of the affected customers lost all their data since they opted for Vaserv's unmanaged service, which fails to include data backup.
It is unknown whether the affected customers will ever be able to retrieve their lost data.
UKFast ensures its clients' data is protected by performing backups included as part of the PROprotection service.