Chapter 2
Computer Viruses, Malicious Logic,
and Spyware
2.1 Computer Viruses
2.1.1 Terms and Definitions
There exist different definitions of the “computer virus“ concept. For the purposes of
this book, the following definition will be used: a virus is a program code embedded
in a program or document that penetrates a computer for unauthorized data destruction, blocking, distortion, copying, and collection or for infecting computers via the
Internet. The main feature of the virus is self-replication, including its ability to
spread from one file to another on one computer or from one computer to another
with neither knowledge nor consent of the user.
Information security specialists often use another definition:
A computer virus is a specially written, usually small program that is able to write
(introduce) its copies (possibly, modified ones) into computer programs located in
executable files, hard drive system areas, drivers, documents, etc. with these copies
retaining the possibility of “self-replication.”
The process of introducing a copy of such a virus into another program (file, hard
drive system area, etc.) is known as infection, and the program itself or a specific
virus-containing object is called infected.
An essential feature of any computer virus is its ability to self-replicate (self-copy)
and get introduced into files, boot sectors of computer drives and digital documents,
remaining unnoticed by the user. The word “virus” used in relation to computer
programs was borrowed from biology precisely because of its ability to reproduce
automatically (self-replicate).
The following stages of virus development are distinguished:
• Hidden stage—the effect of the virus is covert and remains unnoticed by the user;
• Avalanche-like multiplication—the virus multiplies but is not activated yet;
• Active actions—specific harmful actions programmed by its developer are
performed.
© Springer Nature Switzerland AG 2020
A. Belous and V. Saladukha, Viruses, Hardware and Software Trojans,
https://doi.org/10.1007/978-3-030-47218-4_2
101
Computer Viruses, Malicious Logic,
and Spyware
2.1 Computer Viruses
2.1.1 Terms and Definitions
There exist different definitions of the “computer virus“ concept. For the purposes of
this book, the following definition will be used: a virus is a program code embedded
in a program or document that penetrates a computer for unauthorized data destruction, blocking, distortion, copying, and collection or for infecting computers via the
Internet. The main feature of the virus is self-replication, including its ability to
spread from one file to another on one computer or from one computer to another
with neither knowledge nor consent of the user.
Information security specialists often use another definition:
A computer virus is a specially written, usually small program that is able to write
(introduce) its copies (possibly, modified ones) into computer programs located in
executable files, hard drive system areas, drivers, documents, etc. with these copies
retaining the possibility of “self-replication.”
The process of introducing a copy of such a virus into another program (file, hard
drive system area, etc.) is known as infection, and the program itself or a specific
virus-containing object is called infected.
An essential feature of any computer virus is its ability to self-replicate (self-copy)
and get introduced into files, boot sectors of computer drives and digital documents,
remaining unnoticed by the user. The word “virus” used in relation to computer
programs was borrowed from biology precisely because of its ability to reproduce
automatically (self-replicate).
The following stages of virus development are distinguished:
• Hidden stage—the effect of the virus is covert and remains unnoticed by the user;
• Avalanche-like multiplication—the virus multiplies but is not activated yet;
• Active actions—specific harmful actions programmed by its developer are
performed.
© Springer Nature Switzerland AG 2020
A. Belous and V. Saladukha, Viruses, Hardware and Software Trojans,
https://doi.org/10.1007/978-3-030-47218-4_2
101