Mod 2 (Part II)

Malware (Malicious software)

Malware is a software that is used by adversaries to infect and harm peoples' computers. A malware
can have many different effects on a computer which can include causing the infected computer
system to infect other machines on a network or over the internet, letting the attacker access the
infected computer remotely, copying files or keystrokes, displaying advertisements (adware), or
sending a large number of spam emails. New variants of malware are created each day.

The following are the most common types of malware which people need to be aware of:

1) Viruses: this is a malware type that infects computers using a payload inside a file. It can cause
major issues for people. When the virus program is executed it creates copies of itself by infecting
and modifying other computer programs, and in this manner it infects the entire computer which
sometimes could become impossible to recover. An example of how a virus could spread is when
an infected file is copied from a USB drive and onto a computer and is opened by the user. The
virus' payload gets executed when the file is opened and the virus code starts performing its
functions and spreads the infection even further. The virus could also spread to other machines
that are connected to the infected computer. Viruses can be protected against by using various
anti-virus programs.

2) Trojans: it is form of malware that looks exactly like a legitimate software but has inside it a
malicious piece of code. A user can accidentally download a trojan while downloading a software
that they want to use, such as a game. The malicious code inside the trojan performs malicious
activities, such as extracting a user's information. Free software torrents that people download are
commonly used as trojans.

3) Spyware: it is malware that is created to exfiltrate some sort of information regarding a
computer user. The idea behind it is people won't get to know that it exists. The attacker then uses
this information for other evil purposes. There exist many advanced forms of spyware that can be
used by attackers to harm users, and cause financial losses.

4) Keyloggers: these are the forms of spyware that record a user's keystrokes that they enter on
the keyboard. It either stores the keystrokes in a file, or send it to a remote location. Keyloggers
are very stealthy programs.