The term “malware” is short for malicious software and can refer to anything that gets onto your computer without your consent. In essence, it is software that has no legitimate purpose, although the actual intent of the software can vary.
Early types of malware were often created to demonstrate the skill of the developer and so were no more than an annoyance — they often just displayed a joke message. Later versions were much more dangerous because they caused damage by deleting and corrupting data and software. A large proportion of modern malware is intended to make money for the developer by stealing information or by other means.
Malware is a generic term that covers many different types of threat. These include:
- viruses that infect executable software code and then spread when the program is run. You have to actually do something to infect your computer with a virus, such as opening a file or email attachment. As well as spreading, they may cause damage.
- worms are similar to viruses but spread automatically by transmitting themselves over a network to infect other computers. Since the internet is the biggest network of all, their ability to spread is limitless.
- trojan horses are a means of hiding malware to avoid detection. They appear to be genuine software that you want to install and run but contain something less desirable that can cause harm.
- rootkits are designed to conceal other malware by modifying your operating system. As such, they are not harmful in themselves but they prevent threats being detected.
- backdoors may be installed once your computer’s security is compromised. They bypass authentication procedures so that attackers can access your computer remotely and install other malware.
- spyware is intended to gather information from you PC. It may track your browsing habits in order to sell to you more effectively or may steal your personal information, such as bank details. This may include logging your keystrokes to obtain PINs and passwords.
- adware usually displays pop-up adverts on your PC. It often comes with free programs and is a means of recovering their development costs.
Whatever the type of malware, it cannot infect your PC without your help. Even if it is disguised as something else, you have to download and open it for the virus or other form of infection to be released. If your PC is not connected and you never get files from elsewhere, you won’t pick up any malware. However, in the modern age of interconnected PCs, this is hardly likely to be the situation.
The absolute golden rule of malware avoidance is to never open or install anything if you don’t know its source. Do not download programs and files from websites you don’t know. They may contain something nasty that you don’t want. There are, for example, rogue websites that offer free scans of your computer to check for viruses. These always find problems, which are usually fictitious, because they aim to persuade you to download the paid-for version that will fix the problem. All this does is remove the false message; it won’t actually cure anything. On the same lines, don’t open an email attachment from someone you don’t know. Delete the message to avoid the temptation.
Only download and install software from reputable websites. If you’re not sure, do a web search on the company or product and see what comes up. Lots of good reviews will mean you’re safe to download but, if there are reports of problems, look elsewhere.
Another must is to have some reputable internet protection installed, activated and kept up-to-date because the threats change constantly. A good product will have a firewall, will protect you against all forms of malware and remove any problems you already have. Again, check for reputable products before you buy.
If you do the basics, malware should not be a major threat. If you don’t, it can be a big problem.