Virus
First of all we look at how virus work:
A virus is created by a programmer. the virus deliberatly inserts or piggbacks itself into another program on your pc.
So when you open the program that the virus has been inserted into the code is executed before the program itself.
so it hides inside the program and even starts before you have even done anything. A virus is nasty and can spread easily within your pc if it is not detected in time.
Viruses perform the following actions:
- Camouflage
- Replication
- Delivery
- Event Watching
Camouflage:
This is when viruses camouflage themselves. They do this to avoid detection.
They all have different methods of hiding themselves and one of the most common one is to make fake code so that everytime the program with the virus is run it can change the fake code to hide itself.
Replication:
Does exacly what it says really, it makes copies of itself and puts them into other programs so each time the host program with the virus is run it can infect other programs/files.
Delivery:
This is when the viruses "payload" is delivered to the user.Such as deleting system files from ur pc or stealing/changing your account information without you even relising it.
It is basically what the virus was designed to do.
Event Watching
This is when the virus checks for certain conditions and if these conditons are met then the virus can again as mentioned above, deliver its payload.
So now you know what viruses do then what kind of intrustion you can expect,there are many ways of infection, the other common ones would have to be:
Worms which again is software that focuses on network "holes". It uses the security holes to copy itself and insert itself to the machine, and in turn leads to the next one looking for more holes in security and starts replicating itself on othermachines.
Trojan horse is a computer program. A trojan horse which can discise itself to be one thing can infact not do what it requested and instead infect and damage your pc when it is run. They can cause very bad damage to your system but the only good thing about these is that they cannot replicate unlike viruses and worms.
Email viruses are probably the most common of them all in my opinon. Once you open the virus email you become infected , or if there is an attachment and you download this then you most definetly become infected.
This can replicate itself easily by forwarding to hundreds to other email addresses.
How to prevent a Virus from infecting you.
The easist way to prevent yourself from infection is to get some anti-virus software. There are many vendors which offer really good protection and the most relabile one being norton anti-virus and internet security. These anti-virus programs let you detect a virus before it has entered your pc.
They also offer anti-spam and worm protection. For example here is a screen shot of the types of protection.
In this you are protected as long as you keep your definetions.up to date. I do not have the net so that is why my definetions are out of date. .......:-/.
Another way to keep yourself safe is to ensure you have the windows firewall on at all times. Also you can easily download or buy personel firewalls that offer excellent protection by allowing you to accept whatever connections you wish. some of these are norton internet security and also zone alarm which is free to download.