I searched and couldn't find a thread for this and am extremely curious as to why. Due to the severity of this hack, your admin URL, hashes, db logins, etc for WHMCS are all leaked. Most people provide a ftp login directly to their whmcs installation which is stupid enough to hand over to a third party doing integrations but now it's bad enough that hackers got to it.
Here was the notice I got:
Change FTP Details
Unfortunately earlier this evening it would seem that our account (scriptinstallation.ca) was hacked. The person or persons who did the hacking may have had access to our whmcs support tickets and orders so if you have provided us with FTP access details in the past PLEASE CHANGE THESE IMMEDIATELY if you did not do so after your order.
At this time we do not think the hack was done through whmcs - possible using wordpress which we will no longer be using.
Are people just blindly ignoring this message or am I missing something obvious that makes this not a big deal?
Websites get hacked and yes if they use whmcs there have been several known instances lately noting that there are security issues. Just change the password to FTP and another info you gave them and just because you give a company your information it does not mean they will use it to do harm they are telling you so you can be proactive and change the info incase hackers did get to the information.