Computer security techniques are described. One example determines whether to allow a program (e.g., native executable, script, etc.) to execute. This decision is based at least in part on the source of the program, such as whether the program is provided by a privileged source. A privileged program source may be any module, mechanism, or process that can provide executable instructions, such as directory or folder (e.g., on a local disk or network-accessible store), a computing device (e.g., server computer), another program (e.g., a Web server), or the like.