3. Fighting computer infections

Theoretical studies carried out in the 1980s soon led to the definition of a number of techniques and models for effectively combating various computer infections. Although they are more or less easy to implement, their effectiveness varies sufficiently to oblige us to use them jointly. The most important theoretical result is that of Fred Cohen, who demonstrated, in 1986, that determining whether a program is infected is a generally undecidable problem (in the mathematical sense of the term).

An...