There are many types of virus, some of which are called a virus, but strictly speaking are not. This virus guide explains the differences. We also take a look at “Flame” that is currently grabbing all the headlines.

Virus guide and definition

Virus

A computer virus piggybacks on the top of other programs or documents infecting the computer. Some aim to cause damage to the information on the computer. Others attempt to install other software – see below.

Worm

Worms spread by sending copies of themselves across a network or the internet, exploiting vulnerabilities in programs. This is why you must apply all patches and updates to your computers as they become available. Once your computer is infected, it is massively more difficult to clean it. Prevention is better than cure.

Trojan Horse

A program that appears useful but contains something harmful. Usually used to deliver spyware or a virus.

Spyware

Software that obtains information from a user’s computer without thier knowledge. Keyloggers are a good example where they capture the keys you press on your keyboard.

Adware

Programs that secretly gather personal information through the internet and then use it to bombarde you with adverts and spam email.

Malware

Malicious software, is software used or created by hackers to disrupt computer operation, gather sensitive information, or gain access to private computer systems.

Spam

Is in not a virus, however it is just as frustrating. A lot of Anti-virus companies now produce Anti-spam software as well.

Flame

Flame is a particularly nasty and extremely sophisticated piece of malware capable of stealing large volumes of information. It then sends it to a server somewhere in the world. It can record keystrokes, collect passwords, take screenshots, control your webcam, and get information about discoverable Bluetooth devices.

Currently it is suspected to have infected some 600 computers worldwide, mainly in Iran, Israel, Egypt etc. It works by exploiting a flaw in Windows, tricking the computer to believe it is a legitimate Windows software update.

Flame’s creators can supposedly send a “self-destruct” command to the sofware forcing it to wipe itself before it is detected. It is easily the most complex and functionally capable virus to date. At the moment it appears to be used to target governments, and is reported as being used to disrupt the Iranian nuclear programme. If it makes it into the wider community, we should all be very afraid.

Image credit – Teresia