Cybersecurity guide for developing countries – spyware, which, as the name indicates, clandestinely records information. According to the software publisher Webroot, there are over 100 000 different types of spyware on the internet, and over 300 000 sites that host them. A typical PC with an internet connection has an average of 28 spyware programs installed, unbeknownst to the user. More than 80 per cent of company computers have one or more spyware programs. These programs are involved in 70 per cent of all attacks. In addition to these forms of malware, there are viruses and related products (worms, Trojan horses, logic bombs). A virus consists of malicious code that is installed in a system without the user’s knowledge and has the capability of replicating itself (in the case of polymorphous viruses, the replication is not exact, but rather a mutation). It attacks the host environment and contaminates others with which it comes into contact. Viruses can be distinguished on the basis of their signature, behaviour, how they replicate and spread, the types of malfunctions they induce, etc. The purpose of a computer virus, like that of its biological analogue, is to reproduce and propagate itself. It does so by moving from computer to computer, attaching copies of itself to programs and, most commonly, e-mail. This usually occurs in connection with some user action. The damage that a virus causes to the integrity of the contaminated information resources may range from mild annoyances to major destruction, with an impact on system availability and confidentiality. The generic term “virus” is used to designate any harmful computer program (causing infection, destruction, misappropriation of resources, etc.) capable of reproducing and propagating itself. In 2005, an estimated 50 000 new virus were in circulation14. For example, the virus HTML_NETSKY.P, as described by the World Virus Tracking Centre, has infected 855 244 machines around the world since April 2004. The cost, for companies that were infected, was in the order of USD 42 million, according to the Computer Security Institute. The site F-secure.com estimates at four thousand the number of viruses in circulation every day. Worms are bits of computer code that also travel through the net, often on their own without any action by the user. Typically, they are designed to tie up system resources (memory and bandwidth), thereby undermining system availability, or enabling remote control of the infected system. The malware known as Trojan horses is often hidden inside ordinary programs or help files and then infiltrated into systems, where they attempt to take control in order to steal processor time, tamper with or destroy data or programs, cause crashes, conduct snooping or other forms of malicious activity, or merely lie dormant pending a future attack. Logic bombs are viruses that are activated on a particular event (such as birthdays) to attack the host system. None of these should be confused with computer “bugs”, which are programming errors, or, more generally, design flaws that show up as functional problems. The normal way for viruses to propagate and execute is to await inadvertent activation by the user, for example by starting an infected program. In the past, most viruses have been propagated via e-mail attachments, and are commonly activated by clicking on the file icon. 14 Source: IPA/ISEC Computer virus incident report. Cybercrime 37