Monday, June 20, 2011

Virus Protection

Executive Summary:

Computers need virus protection like homes need locks, it’s not strictly necessary unless the neighborhood you are in is bad.  Be careful where you surf on the internet and be extra careful of what you download.  Also be sure of links that you click on from your email. “Free” games and fonts are often a shell for viruses.  Peer to peer file sharing often have viruses as well.  Use virus protection that is free and won’t clog your system like Avast or AVG. Yes, they really are free.  Companies off free virus protection because infected computers are used to attack website and companies with denial of service attacks, gather personal information for identity theft, or host illegal/illicit websites.

Viruses are meant to exploit holes in programs or the operating system.  This is why so many updates are released.  Sometimes the update adds new features, but most also patch previous holes that have recently been discovered.

Think before you click.  Have virus protection as a second line of defense. Always update your computer.

Details:

There are lots of nasty programs floating around the internet.  It used to be that viruses were designed to bring down a computer just for the sheer destruction.  Viruses now don’t harm the infected computer as the programmer want to use the computer for their purposes.  I’m going to use the term “virus” here to refer to true viruses, spyware, adware, and all other malware. 

Viruses are usually found on small private websites.  These websites entice by offering free some type of free product, such as movies, games, fonts, or porn. They can also be reached by sending you an email promising you something interesting or valid but then the link takes you to their site. That is also how phishing works, but that is another blog post. The most sophisticated of these websites only require that you go to the website to be infected by the virus.  This is done by exploiting holes in the web browser you are using.  When a hole is discovered in a web browser, the company that makes it will issue a patch to fix it.  When web browsers are not kept up to date, there are more holes that can be used to install a virus on your computer.  Most web browsers including Firefox and Chrome will update themselves to prevent this problem. This can also be done through peer to peer sharing where a virus is disguised as something you want to download.

Less sophisticated website will ask you to install something.  This can be either disguised as a plug-in for the website to “work properly” or as a full program for you to download and install.  These programs will then either cause adds to appear, tell you there is a virus on your computer that you must pay to remove, track you for either advertising purposes or identity theft, or take secret control of your computer. This can also be done through peer to peer sharing where a virus is disguised as something you want to download.

The most advanced viruses can be targeted directly at a computer connected to the internet and look for a known hole in the operating system and use that to install a virus.  These attacks are often stopped automatically by firewalls on the computer or by the router or modem before ever reaching the computer.

Keeping the operating system updated will prevent or neutralize most viruses. Viruses can’t do what they want without using a hole in the operating system to allow them to do something they are not supposed to.

If your computer is infected by a virus, contact a computer professional immediately.  Often viruses can be removed without too much difficulty.   Occasionally, a virus becomes deeply entrenched in the operating system and removing the virus requires the removal of all data from the hard drive followed by the reinstallation of the operating system and all program and the restoring of data from backups. That is another reason why backing up data is so important, but that’s another blog entry.

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