Cryptolocker first made an appearance last month and since then has been locking up individual computers as opposed to computers located on a network. The virus is usually spread via email through messages sent from an account claiming to be customer support for DHS, FedEx, UPS, etc. These emails have an executable file attached disguised as a PDF. The emails usually ask the recipient to download the form as a PDF, have it signed and then keep the form on file.