Cryptology is everywhere these days. Most users make good use of it even if they do not know they are using cryptographic primitives from day to day. This two-part article series looks at how cryptography is a double-edged sword: it is used to make us safer, but it is also being used for malicious purposes within sophisticated viruses.
Part one introduces the concepts behind cryptovirology and offers examples of malicious potential with the SuckIt rookit and a possible SSH worm. It then introduces armored viruses that use shape shifting (polymorphism and metamorphism) to avoid detection.
The link for this article located at Security Focus is no longer available.
