What are the Potential Computer Threats?

17 July 2010

The following are a few threats that are quite dangerous or annoying in computers.

Early Note
The threats you see here may be related or are in the same category as one another, but this post is mainly just to let you know about the existence of these threats and their names.

The Threats (Malicious Software or Malware)
Viruses are programs that change the computer's behaviour without the knowledge of the user. It usually modifies the values in your computer's registry. It is also capable of copying itself, hiding and even change itself from time to time. The main reason why it is called a virus is due to the capability to reproduce itself, and it has to attach itself to another file.

Types of viruses include:
a) Polymorphic

- Keeps changing its binary data from time to time so that it would not be detected by anti-viruses. Very tricky, and they normally rewrite themselves every time you try to delete them.

b) Parasitic
- Associates or attaches itself with another program so that when it is executed, the virus is executed as well.

c) Boot Sector
- Very trouble some virus that infects the boot process and sequence of the computer. Everytime your computer starts-up, the virus is loaded, even before your OS loads.

d) Stealth
- Designed to evade all error checks and anti-virus scans. Among the techniques used is to duplicate the original uninfected files, so that when a check or scan is performed, they are redirected to these duplicates. Thus, the infected files cannot be detected.

e) Macro
- Used to infect programs that has a sequence of set actions (macro) to be performed on start such as Microsoft Office, but now, Microsoft Office prompts you before enabling macros.

f) Binary
- Requires another component to work together in order to infect the computer. Very hard to detect because the file is basically incomplete, it works together with other files.

g) Joke
- Joke viruses play pranks on the user such as making their icons run away, flipping their screen and so on. Indirectly, it is not very dangerous to the user.

First virus written in Python language.

2. Trojan Horse
Trojan Horses are programs which hide or disguise as another program (mainly a system file) so that the user does not know its existence. It's just like how the Greeks hid inside the Trojan horse to attack Troy. It executes functions that appear safe and legit but is actually malicious, and is mainly used to provide unauthorized access to hackers such as through Backdoors.

3. Worm
Worms generally spread themselves to other computers connected on the network without the knowledge of the user. Most worms are very dangerous and some even have botnet, rootkit and other functions together. Does not need to attach itself to another file.

4. Botnet
Botnet is the use of malicious programs to take control of computers, in which the computers will be called zombies. It is mainly used to launch distributed denial-of-service attacks.

Simple diagram to show how botnet works.

5. Rootkit
Rootkits are programs that grant administrative rights (root) to the hacker without being detected.

6. Remote Administration Tool
RAT is a program that acts exactly like remote administration, where the hacker can see the screen and take control of the user, without his or her knowledge. Under the category of Spyware.

7. Keylogger
A program that records keystrokes typed by the user through the keyboard. Used to steal passwords and other private information. Also under Spyware.

8. Adware
Software that displays or downloads advertisements in the computer, mainly through pop-ups that can be very annoying to the user. Some advertisements link to other threats as well.

Other Threats
Other threats like hackers, social engineering, human error, employee sabotage, fraud, theft and so on, I guess I do not need to explain about this as it is self-explanatory and known by most people.

Get an Anti-Virus.

Make sure you always have a good anti-virus or firewall installed. If you want free software, try COMODO Internet Security, it is very good. Be aware that these threats can often lead to other bad situations such as in the case of identity and data thefts. Be sure to keep your computer healthy!