Computer Viruses

Computer Virus
Computer viruses are malicious programs that are unwantedly installed onto your computer.
Viruses will cause you a range of damage, from a little amount to the entire loss of your computer data.
Almost all viruses are attached to an executable file, which means the virus may exist on your computer but it actually cannot infect your computer unless you run or open the malicious program.
A virus must be spread by a human action, (such as running an infected program) to keep it going.
Viruses are spread by human actions and due to that reason, people will unknowingly continue the spread of a computer virus through sharing infecting files or sending emails with viruses as attachments in the email.
Anti Virus Software
The purpose of anti-virus software is to prevent different types of computer viruses from accessing your personal computer files and causing havoc. Three well known types of anti-virus software include Norton, AVG and McAfee.
Malware is short for malicious software program.The software is used or programmed by the attacker and is specifically designed to damage or disable computer files and computer systems. Examples of malware include Trojan Horses, Worms and computer viruses. Malware gets its name from malicious software because it is software program that acts maliciously (intends to cause harm) to computers.
Trojan Horse
A Trojan Horse is a malicious software program (Malware) that looks like or hides within a legitimate program.
The hidden Trojan appears to be executing (performing) a safe and usual procedure such as "run" or "save" the program.
Unfortunately when either of the two options are chosen, it creates a backdoor which allows it to gain unauthorised access to the victim's computer system.
These backdoor attacks are usually invisible to unsuspecting victims or average users.
Trojans do not try to inject themselves into different computer files or create duplicates of themselves like computer viruses.
Being a type of Malware, Trojans may steal information and personal details or harm the computer system causing loss of data or computer crashes.
Computer Worm
A computer worm is similar to a virus and is also a form of Malware.
Worms spread from computer to computer, but unlike a virus, it has the capability to travel without human action.
A worm uses the file or information transport features on your system and this is what allows it to travel unaided.
Because it is capable of replicating itself on your system, rather than your computer sending out a single worm, it could send out hundreds to thousands of copies of itself which would have a huge devastating effect.
One good example would be for a worm to send a copy of itself to everyone listed in your e-mail address book.
Then, the worm replicates and sends itself out to everyone listed in each of the receiver's address book, and the problem continues .
Worms get their name from their action of worming their ways into the other files to disrupt them.
Spyware is malicious software that is downloaded onto a computer without the owners' knowing and permission.
Its purpose is to send data such as passwords of bank accounts or social networking profiles back from the owner's computer.
Spyware can collect almost any type of data, including personal information like Internet surfing habits, user logins and previously mentioned information.
Spyware may also interfere with the user control of a computer system by installing extra software.
Some spyware can change computer settings and the results include slow Internet connection speeds, un-authorized changes to browser settings, or alterations to software settings.
Ways that Malware invade your computer A*
Malware can invade your computer in the following ways:
1) Through e-mail attachments.
2) By clicking on a web link (advertisement or pop-up) when surfing the web.
3) By downloading a software program that claims to be a cool and legitimate game or picture. (As Trojan Horses do.)
Front Door Attacks A*
Many "front door" attacks require the human action of the legitimate user.
Front door attacks get their name because the user is tricked into opening the door for the attack by their action.
Back Door Attacks A*
Back door attacks don't require the human actions of the legitimate user.
These attacks target vulnerabilities in server software that are running on your computer.
Server Software
Server software (such as a web server) is software that listens for requests that arrive over the internet (e.g. typing the search term "dogs" into a web search engine like Google.)
Server software then attempts to satisfy the requests.(e.g. bringing up the search results for the amount of documents on the internet that contain the search term "dogs".)
Ways that Malware self-replicate (make multiple copies of itself)
A large percentage of malware tries to spread itself automatically.
Malware programs attempt to spread by:
1) Sending out emails with infected attachments
2) Sending out back door attack packets carefully.
Blackhat Hacking
Blackhat computer hackers look for flaws in software to exploit them or to hack into computer systems for malicious purposes.
Whitehat Hacking
Whitehat computer hackers look for flaws in software to fix them or attempt to break into computers to audit their security.
Self-replicating software
Self-replicating software is a type of software that will copy itself throughout a computer system.
World-wide damage
Damages all over the world from just one virus (The I Love You Virus) are estimated at $10 billion dollars.
Defence against attacks
Defending against front door attacks means being careful about what programs you run and what attachments and links you open. Defending against back door attacks means knowing what services are running on your machine and keeping them patched.
Recovering from attacks
It is still a good idea to prepare to recover from an attack if one does occur. Back up personal data and keep track of software installed.