COMPUTER VIRUSES
Computer viruses attack Computers by executing them. The virus
infects programs, and spreads the system. They perform any action including
deleting files, altering data in files, and transmitting confidential
information over a network.
Computer
viruses such as Trojan horses and computer worms are forms of malicious logic.
The important characteristic of malicious logic is that it executes unknown,
unwanted instructions as well as the known set of functions. The unknown,
malicious instructions violate system security. The operating system cannot
determine this, because it does not know that the user is unaware of these instructions
being executed (as the user ran the program containing them).
As
Internet connectivity grows, the ease with which computer viruses can
spread
also grows. In 1984, the first computer viruses were contained at a few sites.
In 2000, the ILOVEYOU program spread worldwide.
A computer virus is a special case of malicious logic (programs that act in violation of the security policy).
Examples of computer viruses are:
- Macro virus
- Boot virus
- Logic Bomb virus
- Directory virus
- Resident virus
Worms
A
computer worm is a self-replicating computer program.
It
uses a network to send copies of itself to other nodes (computers on the
network) and it may do so without any user intervention.
It
does not need to attach itself to an existing program
Spyware
Spyware
is a type of malware installed on computers that collects information about
users without their knowledge.
The
presence of spyware is typically hidden from the user and can be difficult to
detect.
Spyware
programs lurk on your computer to steal important information, like your
passwords and logins and other personal identification information and then
send it off to someone else.
Zombie
Zombie
programs take control of computer and use it and its Internet connection
to attack other computers or networks or to perform other criminal activities.
Phishing
Phishing is a message that tries to trick you into providing information like your social security number or bank account information or logon and password for a web site.
The
message may claim that if you do not click on the link in the message and log
onto a financial web site that your account will be blocked, or some other
disaster.
Spam
Spam is email that you did not request and do not want.
One
person's spam is another's useful newsletter or sale ad.
Spam
is a common way to spread viruses, trojans, and the like.
Adware
Adware (short for advertising-supported software) is a type of malware that automatically delivers advertisements.
Common
examples of adware include pop-up ads on websites and advertisements that are
displayed by software.
Often
times software and applications offer “free” versions that come bundled with
adware.
Ransomware
Ransomware is a form of malware that essentially holds a computer system captive while demanding a ransom.
The
malware restricts user access to the computer either by encrypting files on the
hard drive or locking down the system and displaying messages that are intended
to force the user to pay the malware creator to remove the restrictions and
regain access to their computer.
Anti-Malware program is used to prevent, detect, and remove computer viruses, worms, trojan horses and any other type of malware.
some of Anti-Malware programs are:
- Antivirus program
- Anti-spyware program
- Anti-spam program
- Firewall
