Two common types of virus are as follows:
* Worms (can spread between computer systems by using network links)
* Trojans (can install themselves on computer systems without a user’s knowledge and offer backdoor access to hackers, but cannot spread between computers)
Both types of virus can be difficult to remove unless antivirus is installed on your computer system prior to its infection. This is due to the fact that a lot of viruses nowadays attempt to disable any new antivirus programs that are installed after virus infection of a computer has already taken place.
The best way to keep your personal information and computer virus-free is to have an up-to-date security program that includes both anti-virus and anti-spyware capabilities. Keeping your chosen program up-to-date is crucial as new viruses and spyware are being detected every day.
There are a number of ways in which malicious software can be transmitted to a computer system. Whilst the most common method is via networks such as the Internet, it is important to remember that, although increasingly rare these days, CDs, as well as other types of external media, can also contain viruses and spyware.
Whilst external media from trusted companies does not usually contain malicious software, home-made CD’s, i.e. those containing personal files or backed up data, can contain viruses and therefore should only be inserted into computers with up-to-date security software.
This is especially important for business users, as loss or corruption of data can have serious consequences for these users, due to the fact that such organisations are largely reliant on computers in order to trade with customers.
It is also important to have a working firewall somewhere on your system. This can be either a hardware firewall such as a router device, or for those users who are connected directly to the Internet, a software-based firewall program.
This is mainly because there are some viruses, a well-known example being the MSBlast worm, that can spread by probing unsecured computers and installing copies of themselves on there, often without the user’s knowledge.
The first signs that users often get of such viruses, assuming that they have no anti-virus software, is either corrupted files, or in the case of MSBlast, a shutdown dialog box giving the user a certain amount of time before their computer automatically shuts down.
Due to the fact that software can be compromised far more easily than hardware, the best thing to do is to have hardware firewall protection wherever this is possible. Fortunately, most ISPs issue their users with routers, meaning that they are protected from some security threats without having to adjust settings or install software programs on their computer systems.
Although most of these viruses are several years old, there are still copies roaming the Internet, which means that it is highly inadvisable to plug an unsecured computer directly into the Internet, i.e. not behind any sort of router or software firewall program.