CRE Loaded 6,1 Site Hacked with Bots Virus Injection

CRE loaded 6,1 We are constantly being hacked and viruses are being injected on site with Bots, We have clean restored and willing to remove admin panel to prevent further attacks. It seems after removing admin panel the bots still manage to upload a Virus Kryptik trojan on the site. We are running 1 Database across 4 sites. The other 3 sites do not have admin panel and were not hacked so it seems, But our main site which holds the Database is being hacked. We need someone to secure the Sites, We can use Clean restores to save cleaning up. The point is to secure the site from Attacks and prevent future Hacks from bots or any virus injection. Budget is around $150.00 Approx. We need someone who has dealt with CRE loaded hacks in the past and can fix this. If this is a bot attacks we need strong Robot text files [login to view URL] file allowing only search engines but blocking out all other unknown robots. Previous Programmer was unable to stop and never come accross this problem in the past there for had to give up.