Recognition and removal of macro viruses

摘要

Apparatus and method for detecting the presence of macro viruses within a digital computer (1). An application program (5) is associated with the digital computer (1). A global environment (13) is associated with the application program (5). The application program (5) generates at least one local document (11). Macros contained within the global environment (13) and the local document(s) (11) are executed in a simulated manner by an emulator (15). At least one preselected decision criterion is used by a detection module (17) to declare when a macro virus is deemed to be present. Such a criterion is typically the presence of a bidirectional macro, i.e., a macro that copies from a local document (11) to the global environment (13) and vice-versa. Macros deemed to be viruses are preferably deleted by a repair module (19). Additional deletion criteria may include the presence of macros that have the same source name or the same destination name as a bidirectional macro. In the preferred emulation steps, emulator (15) tests all of the macros associated with computer (1) in two steps. The first step assumes that the macros reside within the global environment (13), regardless of whether they reside within the global environment (13) or within a local document (11). The second step assumes that the macros reside within a local document (11), regardless of whether they reside within a local document (11) or within the global environment (13).