19. The computer system of claim 18 , wherein the identified antimalware applications are ranked based on which antimalware application optimally protects the user according to the determined forms of malware the user is most likely to encounter.
18. A computer system comprising the following: one or more processors; system memory; and one or more computer-readable storage media having stored thereon computer-executable instructions that, when executed by the one or more processors, causes the computing system to perform a method for ranking antimalware programs according to the program's ability to protect against user-specific threats, the method comprising: accessing information indicating one or more clusters of persons that have encountered at least one form of malware comprising a computer malware that is capable of infecting a computing system, the persons being associated with a user; determining, from the accessed information, which one or more forms of malware the user is most likely to encounter based on the user's interactions with the clusters of persons that have encountered malware; and identifying one or more antimalware applications based on which antimalware application optimally protects the user according to the determined forms of malware the user is most likely to encounter.