VIRUSES, WORMS, BACKDOORS AND ROGUE SECURITY
There is a category of malware which can damage and destroy programs and data and compromise
computer functions. The two most common types of malware belonging to this category are viruses and
worms.
A virus is a software program that is designed to copy itself over and over and spread to other computers. It
attaches itself to a program and executes the code when the user launches the infected program. Viruses
can cause a lot of damage, waste of time and financial loss for businesses. They can also corrupt software
drivers which allow hardware devices to communicate with the computer, but luckily, they cannot
physically damage the hardware.
In the 1980s, people who created viruses had a certain misplaced sense of humour. For example, there was
a virus that caused all the characters on screen to drop into a heap at the bottom of the display. It was very
annoying, but relatively harmless. In 1986, viruses were defined mathematically by Fred Cohen and later,
some really nasty versions came out with the deliberate intent to corrupt and delete files as well as trying
to copy the virus everywhere. A virus called Melissa, for example, was so effective in spreading itself that
many large companies had to shut down their email system until the virus could be neutralised.
A worm is a program that spreads over computer networks by exploiting vulnerabilities in the operating
system without the need for the users to do anything. The origin of worms goes back to the 1980s, when
researchers were looking for programs which could distribute themselves automatically across the Internet.
Worms can cause harm to host networks by consuming bandwidth and overloading web servers. They may
also contain a payload, i.e. a piece of code capable of damaging the host computer. The malicious program
is often a downloader, .e. a very small program that later connects to a remote computer to download
more substantial malicious software. Moreover, they can take control of host computers, either to steal
sensitive data or convert them into remote-controlled zombies or bots. Sometimes, they infect computers
by exploiting bugs in legitimate software. Backdoors and rogue security facilitate malicious attacks.
Backdoors find a secret way to enter the computer system and provide a network connection for hackers or
other malware to enter or for viruses and spam to be sent.
Rogue security pretends to be a program which removes malware infections, but actually it is malware that
turns off the real antivirus program installed in the computer.
TRADUZIONE
Esiste una categoria di malware che può danneggiare e distruggere programmi e dati e compromettere le
funzioni del computer. I due tipi più comuni di malware appartenenti a questa categoria sono i virus e i
worm. Un virus è un programma software che è progettato per copiare sé stesso più e più volte e
diffondersi in altri computer. Si attacca a un programma ed esegue il codice quando l'utente fa partire il
programma infetto. I virus possono causare molti danni, spreco di tempo e finanziarie per le aziende.
Possono anche corrompere i driver software che permettono ai dispositivi hardware di comunicare con il
computer, ma fortunatamente non possono danneggiare fisicamente l'hardware.
Negli anni '80, le persone che creavano i virus avevano un senso dell'umorismo inappropriato. Per esempio,
c'era un virus che creava un mucchio di caratteri nella parte inferiore del display, facendoli cadere tutti
dallo schermo. Era molto fastidioso, ma relativamente innocuo. Nel 1986, i virus furono definiti
matematicamente da Fred Cohen e più tardi, uscirono alcune versioni davvero maligna con l'intento
deliberato di corrompere e cancellare i file, oltre a cercare di copiare il virus ovunque. Un virus chiamato
Melissa, per esempio, fu così efficace nel diffondersi che molte grandi aziende dovettero chiudere il loro
sistema di posta elettronica fino a quando il virus non fu neutralizzato.
