1. COMPUTER VIRUSES By Gobetti Andrea & Salvestrini Luca

2. HISTORY OF VIRUSES Virus appeared in 1988 on Machintosh In 1989 appeared on IBM/MS-DOS systems.

3. STRUCTURE OF A VIRUS The virus is written to self-replicate Two parts: replication engine and payload The origin is external to the computer

4. TYPES OF VIRUS File infectors Boot-recors infectors Macro viruses Trojan horses Worms Logic Bombs

5. MACRO VIRUSES Infect using macro utilities Application-specific Not specific to OS

6. WORMS (rabbits) Resides in active memory (RAM) Network worms: different segments One coordinates the others (octopuses) Send copies via e-mail or IRC

7. LOGIC BOMBS Wait for a trigger Can be used by ethical hackers

8. TROJAN HORSES Looks a useful software but it’s a virus Can also be a spyware Can create back doors Composed by two parts: Client part on the attacker system Server part on the victim system

9. VLADIMIR VETROV (1928-1985) He was a KGB spy but worked also for the NATO (double agent) Code named Farwell by the french intelligence service The soviet union needed computer control systems for the trans-Siberian gas pipeline trojanned software > largest non-nuclear explosion ever