Information is received from a set of peer clients associated with a client, the information indicating likelihoods of peer client exposure to malware threats. An environmental safety score associated with the client is determined based, at least in part, on the information received from the set of peer clients, wherein the environmental safety score indicates a likelihood that the client is exposed to malware threats. A set of malware signatures is retrieved from the server at a time determined responsive to the environmental safety score and stored.