it's not their fault...
your computer is infected...
I know since I've been there already..
you need to install
Nod32 +
Malwarebytes Anti-Malware and scan it. I guess you're still on XP so moving to Windows 7 would also help.
After that
if you use Filezilla - move to Filezilla portable
if you use Total Commander - download latest version and use master pasword for FTP
also use something for storing passwords in browser like RoboFrom, Keepass or similar...