Finishing the Work
To be safe, I ran a complete virus scan, ran CHKDSK, and examined the security logs. Fortunately, there were no viruses, but "someone" was still trying to log into the server! Of course, it was a bogus account from the "home.com" network. Nice try, but you now need a valid user name and password to access this FTP server.
As a follow-up, I checked the Administrators, Domain Admin, Server Ops, and Backup Ops groups to be certain that there weren't any bogus accounts lurking around. Next, I confirmed with my client that the firewall was still working and the accounts that needed access to the server could reach their data. Finally, I tried to remotely access the FTP, Web, and server through a variety of tools. I could not access the site without proper credentialsand even then the NTFS permissions were in place.