Kinds of Malicious Code

• A “virus” is usually a term reserved for malicious code that has the ability to pass on malicious code by modifying other non-malicious programs.

  • Many programs start with a jump statement that launches execution somewhere later than the start of the program. By altering this jump statement and inserting executable instructions in the segment that would have been jumped over.
  • Code can also be relocated.
  • Transient or resident viruses are possible. (TSR yick)