An "attack site" refers to a website that is used to harm or compromise the security of a visitor's computer or steal their personal information. Full definition
If something breaks because of a plugin update or if a hacker attacks the site a professional website person would need to be called in. (katetilton.com)
The WordPress Support Forum and WordPress's «My Site Was Hacked» FAQ can be priceless resources in finding what kind of attack your site has suffered, and how to fix it; there are also many sites and blogs that have attack stories and solutions. (stemlegal.com)
(He can check that the code is shuffling and whether anyone has attacked the site by reviewing the program's logs). (sciencedaily.com)