1. A computer-implemented method for using reputation information to evaluate the trustworthiness of files obtained via torrent transactions, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising: identifying, by the computing device, a torrent file that comprises metadata for facilitating a torrent transaction for obtaining a target file via a peer-to-peer file-sharing protocol; identifying, by the computing device, a plurality of computing systems involved in the torrent transaction, the plurality of computing systems comprising at least one of: an original seeder that uploaded the torrent file to a torrent hosting site; a peer capable of providing at least a portion of the target file; a peer attempting to download at least a portion of the target file; obtaining, by the computing device, reputation information for the plurality of computing systems involved in the torrent transaction, wherein the reputation information identifies a community's opinion on the trustworthiness of the plurality of computing systems involved in the torrent transaction based at least in part on results of at least one previous torrent transaction in which the plurality of computing systems were involved; calculating an average peer reputation based at least in part on the reputation information for the plurality of computing systems; determining, by the computing device, that the target file represents a potential security risk based at least in part on the calculated average peer reputation; performing, by the computing device, a security action on the target file.
1. A computer-implemented method for using reputation information to evaluate the trustworthiness of files obtained via torrent transactions, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising: identifying, by the computing device, a torrent file that comprises metadata for facilitating a torrent transaction for obtaining a target file via a peer-to-peer file-sharing protocol; identifying, by the computing device, a plurality of computing systems involved in the torrent transaction, the plurality of computing systems comprising at least one of: an original seeder that uploaded the torrent file to a torrent hosting site; a peer capable of providing at least a portion of the target file; a peer attempting to download at least a portion of the target file; obtaining, by the computing device, reputation information for the plurality of computing systems involved in the torrent transaction, wherein the reputation information identifies a community's opinion on the trustworthiness of the plurality of computing systems involved in the torrent transaction based at least in part on results of at least one previous torrent transaction in which the plurality of computing systems were involved; calculating an average peer reputation based at least in part on the reputation information for the plurality of computing systems; determining, by the computing device, that the target file represents a potential security risk based at least in part on the calculated average peer reputation; performing, by the computing device, a security action on the target file. 5. The method of claim 1 , wherein identifying the plurality of computing systems involved in the torrent transaction comprises: monitoring network traffic; parsing the network traffic to identify an IP address of at least one of the plurality of computing systems involved in the torrent transaction.