Abstract: In one aspect, an executable computer file is partitioned into basic blocks of code. At least some basic blocks are translated into translated basic blocks. At least some translated basic blocks are linked in memory of a computer. At least some translated basic blocks on the computer are executed so as to enable the file to be unpacked or decrypted. In this way, the file can be analyzed to determine whether the file is or should be classed as malware. In another aspect, at least a read page of cache memory is created for at least some basic blocks and at least a write page of cache memory is created for at least some basic blocks. During the execution of a basic block, at least one of the read page and the write page is checked for a cached real address corresponding to the virtual address that is being accessed for said basic block.

Abstract: In one aspect, a method of classifying a computer object as malware includes receiving at a base computer data about a computer object from each of plural remote computers on which the object or similar objects are stored. The data about the computer object received from the plural computers is compared in the base computer. The computer object is classified as malware on the basis of said comparison. In one embodiment, the data about the computer object includes one or more of: executable instructions contained within or constituted by the object; the size of the object; the name of the object; the logical storage location or path of the object on the respective remote computers; the vendor of the object; the software product and version associated with the object; and, events initiated by or involving the object when the object is created, configured or runs on the respective remote computers.