1. An apparatus for protecting resources of a computing system from a malicious code, the apparatus comprising: a compulsory resource storage configured to provide one or more compulsory resources or a list of the compulsory resources, wherein the compulsory resources are at least a part of the resources classified as being compulsory for execution of a program on the computing system; a modified resource generation unit configured to generate a modified resource; and a resource control unit configured to perform selective virtualization, wherein the selective virtualization includes: determining, when the program requests access to a target resource among the resources of the computing system, whether or not the access-requesting program is a vulnerable program; when the access-requesting program is determined to not be a vulnerable program, executing the access-requesting program, when the access-requesting program is determined to be a vulnerable program, creating a separate space for execution of the access-requesting program and further determining whether or not the target resource is one of the compulsory resources; when the target resource is one of said compulsory resources, performing an operating system (OS) level virtualization, as follows: (a) when the access request is a read request, permitting access by the vulnerable program to the target resource, and (b) when the access request is a write request, generating a copy of the target resource and then permitting access to the copy of the target resource; and when the target resource is not one of said compulsory resources, causing the modified resource generation unit to create a modified resource and permitting the vulnerable program to access the modified resource instead of the target resource, and wherein the modified resource generation unit is configured to generate the modified resource such that the modified resource is a modified copy of the target resource that includes content different from that of the target resource and that is stored separately from the target resource.