Anti-Malware development

I run a web hosting company and we are looking to develop our own Anti-Malware Scanner - something like this: [login to view URL] This software should not require software installs on the target server (will just read files from the web) and needs to work on all platforms (linux and windows). Once developed we need to construct a WHMCS plugin where clients will run this service from. WHMCS is our billing and support platform ([login to view URL]). I want a client to be able to login and add websites to monitor and be able to do manual scans. The scan should include up-to-date exploits and checks against the major search engine and browser blacklists. They should also be able to schedule scans and have the results emailed to them. As the host we should be able to limit (1) the amount of domains a client can scan (allowing them to add more for a premium) and (2) the frequency of scanning (once a day being standard, allowing to add more frequency for premium). I'm unsure as to what backend tool can be used. Right now we do scans on Linux servers with Maldet but that is software that needs to be installed on the server. This is something that would need regular updates just like anti-virus scanner on a PC. I wondered if using this was a possibility: [login to view URL] [login to view URL]~provos/spybye/ I'm wiling to pay for a commercial application as the backend software if the EULA allows the platform built on it to be resold. GeoTrust has an anti-malware product and uses a Symantec product as its backend. It's just a question of finding the backend software and integrating with a web GUI. I'm hoping there is a cost-effective solution out there. It might be as easy as finding a source like Symantec, paying them to use their backend malware signatures and building a plugin using APIs. If you bid for this I need to know a basic outline of how you think this can be achieved.