Has a cryptovirus ever been written?
Yes. The notion of cryptoviral extortion was introduced in [Yo95] (i.e., the use of public key crypto to hold data hostage). The first cryptovirus was “implemented” as part of that Masters Thesis. Also, the thesis contains the actual RSA key pair that the experimental cryptovirus used. A summary of the first cryptovirus appears in [YY96a]. The virus was programmed using ANSI C and Motorola assembly and spread on a Macintosh SE/30. It used AT&T’s truerand to generate random bits. It used Wheeler and Needham’s Tiny Encryption Algorithm (TEA) and RSA. RSA was implemented using the GNU multiprecision library. Careful measures were taken to ensure that the virus did not spread into the wild.
