Web site hygiene-based computer security

A system for providing computer security, comprising:

• a non-transitory computer-readable storage medium storing executable computer program modules comprising:
• a hygiene cache module for receiving from a plurality of clients data describing client hygiene scores for the clients and describing a plurality of web sites visited by the clients, and for storing the client hygiene scores associated with the plurality of clients, the client hygiene score for a client calculated responsive to an amount of malicious software detected at the client;
• a hygiene computation module for calculating a secondary hygiene score for a web site of the plurality of web sites visited by the clients based at least in part on a number of clients with predominately good client hygiene scores and a number of clients with predominately bad client hygiene scores that visited the web site;
• and
• a reputation computation module for calculating and storing a reputation score for a file hosted by the web site responsive to the secondary hygiene score of the web site, the reputation score representing an assessment of whether the file is malicious;
• and
• a processor for executing the computer program modules.

A computer program product having a non-transitory computer-readable storage medium with executable computer program instructions embodied therein for providing security, the computer program instructions comprising:

• a hygiene cache module for receiving from a plurality of clients data describing client hygiene scores for the clients and describing a plurality of web sites visited by the clients, and for storing the client hygiene scores associated with the plurality of clients, the client hygiene score for a client calculated responsive to an amount of malicious software detected at the client;
• a hygiene computation module for calculating a secondary hygiene score for a web site of the plurality of web sites visited by the clients based at least in part on a number of clients with predominately good client hygiene scores and a number of clients with predominately bad client hygiene scores that visited the web site;
• and
• a reputation computation module for calculating and storing a reputation score for a file hosted by the web site responsive to the secondary hygiene score of the web site, the reputation score representing an assessment of whether the file is malicious.