My almost ci site hack

A long time ago I had this happen. I wanted to blame all of the usual suspects, but in the end I found that it was my use of plain FTP, and the fact that another computer on my network was infected with many viruses / malware. I even changed my password to FTP, but that didn't help because that other computer was sniffing network traffic, and as soon as I used another password it would grab it.

OP never said if he/she was using plain FTP. What is it OP? Ideally use SFTP, FTPes, or anything besides plain FTP.

That i understand, but why my only ci website are hacked not others that i have made in other programming language.

we need more infos. without infos we can not help.

changed the hacker some files or only the output of the site?