Computer Security | Computer Virus | Symptoms of Virus Attack | Some tips to maintain a Virus free Computer

computer security

What is Computer Security?

  • Computer security is a branch of computer technology known as information security as applied to computers and networks.
  • The objective of computer security includes protection of information and property from theft, corruption, or natural disaster while allowing the information and property to remain accessible and productive to its intended users.

Security Architecture

  • Security Architecture can be defined as the design artifacts that describe how the security controls (security counter measures) are positioned and how they relate to the overall information technology architecture.
  • These controls serve the purpose to maintain the system’s quality attributes, among them confidentiality, integrity, availability, accountability and assurance.
  • Computer security involves providing appropriate levels of assurance of:
  • Availability of computing services and data/information stored in computing systems.
  • Confidentiality of data/information stored in computing systems.
  • Integrity of computing systems and data/information stored there in.
  • Auditability of usage of computing systems and access to data/information stored there.
  • Non-reputability of transactions initiated by individuals and organizations.

Security by Design

  • The technologies of computer security are based on logic.
  • As security is not necessarily the primary goal of most computer applications, designing a program with security in mind often imposes restrictions on that program’s behavior.

There are 4 approaches to security in computing; sometimes a combination of approaches is valid:

  • Trust all the software to stand by a security policy but the software is not trustworthy (this is computer insecurity).
  • Trust all the software to stand by a security policy and the software is validated as trustworthy (by tedious branch and path analysis for example).
  • Trust no software but enforce a security policy with mechanisms that are not trustworthy (again this is computer insecurity).
  • Trust no software but enforce a security policy with trustworthy hardware mechanisms.

computer virus

Computer Virus

  • A Virus is a small piece of software that piggybacks on real programs in order to get executed.
  • Once it’s running, it spreads by inserting copies of itself into other executable code.
  • A virus is a software code which harms the computer.

Symptoms of Virus Attack

  • Computer runs slower than usual.
  • Computer no longer boots up.
  • Screen sometimes flickers.
  • PC speaker beeps periodically.
  • System crashes for no reason.
  • Files/directories sometimes disappear.
  • Typical things that some current Personal

Computer (PC) viruses do:     

  • Display a message
  • Erase files
  • Scramble data on a hard disk
  • Halt the PC
  • Many viruses do nothing obvious at all except spread

Some tips to maintain a Virus free Computer

Email is one of the common ways your computer can catch a virus.

  • Stay away from SPAM emails.
  • Open only those emails that come from trusted sources (example: people in your contact list).
  • If you are using your own private email host (other than Gmail, yahoo, Hotmail etc.) then it is highly recommended that you use good anti-spam software.
  • Never click on any links in emails that come from untrusted sources.

USB thumb/pen drives are another common way in which viruses spread.


  • Perform a virus scan before copying any data onto your computer.
  • Never double-click the pen drive (to open it).
  • Instead right-click on it and select the option “open”.
  • The internet is the main source of malicious programs including viruses, worms, Trojans.
  • Don’t click on pop-up windows that announce a sudden disaster or announce that you’ve won an hourly prize.
  • These are often attempts by virus writers to mislead Internet users and you should never trust them.
  • You can also use a pop-up blocker to automatically block those pop-ups.
  • Use Google Search with care.


Use Google Search with care

  • It is quite simple for a malicious website to get listed in the search results.
  • To avoid visiting those malicious websites, you can download and install the AVG Link Scanner, which is freeware.
  • This tool can become very handy and will help you to stay away from malicious websites.


Install good antivirus software and keep it updated.

  • Also perform a full system scan periodically.
  • Turn on the automatic update feature.
  • This is the most essential task to protect your PC from viruses.
  • If PC security is your first priority then it is recommended that you go for shareware antivirus software over the free ones.
  • Most antivirus software supports the Auto-Protect feature that provides real-time security for your PC.
  • Make sure that this feature is turned on.
  • Never open any email attachments that come from untrusted sources.
  • If it is a picture, text or sound file (these attachments end in the extensions .txt, .jpeg, .gif, .bmp, .tif, .mp3, .htm, .html, and .avi), you are probably safe, but still do a scan before opening.
  • Do not use disks that other people gave you.
  • The disk could be infected with a virus.
  • You can run a virus scan on it first to check it out.
  • Set up your Windows Update to automatically download patches and upgrades.
  • This will allow your computer to automatically download any updates to both the operating system and Internet Explorer.
  • These updates fix security holes in both pieces of software.
  • It is not recommended to visit websites that feature illegal information such as cracks, serials.
  • They contribute greatly to the spreading of viruses and other malicious programs.