Computer viruses are, like their biological namesake, programs that infect your system and multiply. Viruses have many symptoms: some can simply slow down your computer whilst others can have more severe effects like moving documents and/or deletion of documents or programs. No matter the severity of the virus and its symptoms they should be dealt with by an up-to-date anti-virus program and security software, as systems with out-of-date protection are more susceptible and at risk.
Computer viruses are most commonly passed through interaction over the internet, whether they are attached to (or are disguised as) downloaded files or emails sent from friends with already compromised systems. Viruses can be passed from computer to computer without the owners knowing they are passing them along. There are 3 basic types of viruses: Trojan Horses, Worms and Email Viruses.
Trojan Horses – A Trojan – named after the Greek army’s tactic of hiding their soldiers in a giant wooden horse that was sent as a gift to the city of Troy (In Homer’s epic Illiad) – disguises itself as a document or file of interest, e. g. a sound-bite or song for a music lover, a new patch for an MMO or game for gamers or a picture/video. These viruses do not multiply but rather make your computer’s protection weaker and thus makes your system more susceptible to viruses and other kinds of malicious software.
Worms – The Worm-style of virus is a program that, once inside your system, multiplies and scans for flaws or loop-holes in your security systems and protection. The Worm-style virus attempts to spread itself through a large network by taking advantage of the loop-holes and flaws that it finds or sending itself through the intranet of the network to other computers. Email Viruses – Email viruses use (as suggested by the name) emails to send itself to other computers and spread itself, they often forward themselves from infected computers.
Prevention and protection from these types of viruses are simple; usually an up-to-date anti-virus software and security program is all that is needed. Recommended companies that supply anti-virus software and other protection/security programs are AVG, Symantec, Avast! And Sophos. Anti-Virus software is a useful tool against viruses, which is a given. Having been specifically designed to combat the viruses, any good A-V software will regularly scan, at routine intervals that you can set, your computer, stored files and hard drives for viruses.
Most decent A-V software will give you several options, allowing you to enact a scan at your discretion, the depth of the scan and connects you, through the software and internet, to a database which stores data on the viruses found on a fellow A-V user’s computer. Another feature most A-V software gives is the automatic scan of any files you download through your web browser, or the option to scan any file you already have downloaded on to your system. Downloading from the internet is risky, you can never be sure of where the file is coming from.
Viruses, as stated above, can be, and often are, disguised as files of interest for certain people to fall foul of. As well as receiving viruses through an email system, which are usually disguised as a file attached to an email from an unknown sender or random contact, there are other problems associated with email systems. These problems are things such as: files not attaching to emails, mail from misrepresented or unknown users and inappropriate content in junk-mail.