In information security , computer virus is a manmade program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes. From behavior computer virus in a way is a similar biological virus which pervasions by inserting itself into living cells. Cell by cell and all organisms (computer) is ridden virus cells.
Without computer viruses there are separated two other types of malicious computer programs - viruses.
Trojan Horses
As already from this virus type name we can imagine, Trojan horses are programs that pretend to be legitimate software, but actually carry out hidden, harmful functions. Trojans can't replicate themselves that mean, they can't expand so fast as other virus types. But often they work together with viruses.
Worms
Worms are similar to viruses but do not need a carrier program or document. Worms simply create exact copies of themselves and use communications between computers, for example e-mail, to spread.There are different types of computer viruses with different influence. Some viruses are fairly harmless or only annoying, but there are viruses that can create inconceivable damages.
Some things what virus can do with computer:
* Slow down e-mail ? generating huge e-mail traffic and slowing down servers;
* Steal confidential data ? for example, recording user's keystrokes;
* Use your computer to attack websites;
* Let other user hijack your computer ? allowing to connect to your computer and use it for their own purpose;
* Corrupt data ? making changes in some documents;
* Delete data ? all or only some part data on your HDD;
* Play pranks;
* Damage credibility ? forwarding itself from your computer to your friends or even business partners;
* Cause embarrassment - for example, replacing one word in all documents with other.
Every year computer viruses activity brings to company several million dollars damages. Year for year this number of damage increase!
Because it is so important that every people get information security awareness training
