Methods and systems for protecting a virtual machine network are disclosed. In an embodiment, a method involves storing an application whitelist including application-to-user associations in memory such that the application whitelist is immutable by a guest virtual machine, receiving a request to execute an application including an application identifier and a user identifier, comparing the application identifier and the user identifier of the request with the application whitelist, and generating an execution decision indicating whether the requested application can execute on the guest virtual machine.