Hi tomer628,
... you could at least provide some informations about your server, the used Plesk version ( incl. #MU ) and provide some depending log - entries, which lead to a conclusion, that your server is "on attack".
The MORE informations you provide, the better will be possible suggestions, how you could solve your issue/problem/error, but without any decent informations, it is impossible for people willing to help you, to answer your issue/error/problem/question.