Create wordpress under different users

Hi everyone,

I've my hosting in OVH with several domains. All of them are using WordPress and I use the "modules" option to set up the different web pages.

My problem is that when one of the WordPress suffers an attack, all the other web pages seem to be rapidly infected. A colleague told me that if I set up the different WordPress under different users, it might help to reduce the risk of extending the infection over the others.

Is this possible? I saw that I can create users, but not sure how to really use them. When I try to add again the new web pages using the "modules" option I didn't see any option to do it under any different user.

Any help on this will be appreciated

thanks