Viral Attacks On UNIX System Security
Article from Tom Duff, August 1987
Thu Oct 14 21:29:40 2021 - permalink -
Executable files in the Ninth Edition of the UNIX system contain small amounts of unused space, allowing small code sequences to be added to them without noticeably affecting their functionality. A program fragment that looks for binaries and introduces copies of itself into their slack space will transitively spread like a virus. Such a virus program could, like the Trojan Horse, harbor Greeks set to attack the system when run by sufficiently privileged users or from infected set-userid programs.