FileZilla has an evil twin that steals FTP logins.
Maliciously modified versions of the popular FTP application FileZilla look and act just like the real thing, but include extra code that steals the login data typed in by users and sends it to an unauthorized server using the same FTP operation launched by the user without going through a firewall that might spot what it's doing
Learn more:
http://it.slashdot.org/story/14/01/28/0332253/filezilla-has-an-evil-twin-that-steals-ftp-logins
http://blog.avast.com/2014/01/27/malformed-filezilla-ftp-client-with-login-stealer/#.UuZqGNJBae8.twitter
Protect yourself by downloading from a trusted source.
https://filezilla-project.org