12.3.2 Different Ways of Attack Made by Hacker Electronic communication networks and information systems are now an essential part of daily lives and are fundamental to the success of the economy Networks and information systems are converging and becoming increasingly interconnected. Despite the many and obvious benefits of this development, it has also brought with it the worrying threat of intentional attacks against information systems. These attacks can take a wide variety of forms including illegal access, spread of malicious code and denial of service attacks. It is possible to launch an attack from anywhere in the world, to anywhere in the world, at any time. New, unexpected forms of attacks could occur in the future. Threats against computer systems include 1. Unauthorized access to information systems This includes the notion of"hacking". Hacking is gaining unauthorized access to a computer or network of computers. It can be undertaken in a variety of ways from simply exploiting inside information to brute force attacks and password interception. It is often though not always with malicious intent to either copy, modify or destroy data. Intentional corruption of websites can be one of the aims of unauthorized access 2. Disruption of information systems ber, Different ways exist to disrupt information systems through malicious attacks. One of the known ways to deny or degrade the services offered by the Internet is a" denial of service attack. In a way this attack is similar to fax machines being flooded with long and repeated essages. Denial of service attacks attempt to overload web servers or Internet Service Providers with automatically generated messages. Other types of attacks can include disrupting servers operating the domain name system and attacks directed at"routers" Attacks aimed at disrupting systems have been damaging for certain high profile websites like portals. Companies rely on th availability of their websites for their business and those companies that depend on it for just in time"supply are particularly vulnerable Execution of malicious software that modifies or destroys data The most well known type of malicious software is the virus. Infamous examples include the I Love You"and"Melissa"viruses. About 1l of European users have caught a virus on their home PC. There are other types of malicious software. Some damage the PC itself, whereas others use the PC to attack other networked components. Some programs often called"logic bombs' can lie dormant until triggered by some event such as a specific date, at which point they can cause major damage by altering or deleting data Other programs appear to be genuine, but when opened elease a malicious attack often called Trojan Horses. Another type is a program often called a worm that does not infect other programs as a virus, but instead creates copies of itself, which in turn create even more copies and eventually swamp the system 4. Interception of communications Malicious interception of communications compromises the confidentiality and integrity equirements of users. It is often called"sniffing 5. Malicious misrepresentation Information systems offer new opportunities for misrepresentation and fraud. The taking of someone else's identity on the Internet, and using this for malicious purposes, is often called 12.3.3 Main Technological Skills to Prevent from Hacker If you're worried about viruses or hackers wreaking havoc on your syst some precautionary measures-and breathe a little easier. The best way to make sure your computer is ready to do battle with its many potential enemies is to load it up with software designed to protect it from potential hackers and evil viruses Think of your computer as an extension of yourself: You don 't run into the street without looking both ways and you dont blindly enter crime-ridden areas without taking precautions. Simply put,12.3.2 Different Ways of Attack Made by Hacker Electronic communication networks and information systems are now an essential part of our daily lives and are fundamental to the success of the economy. Networks and information systems are converging and becoming increasingly interconnected. Despite the many and obvious benefits of this development, it has also brought with it the worrying threat of intentional attacks against information systems. These attacks can take a wide variety of forms including illegal access, spread of malicious code and denial of service attacks. It is possible to launch an attack from anywhere in the world, to anywhere in the world, at any time. New, unexpected forms of attacks could occur in the future. Threats against computer systems include: 1. Unauthorized access to information systems This includes the notion of "hacking". Hacking is gaining unauthorized access to a computer or network of computers. It can be undertaken in a variety of ways from simply exploiting inside information to brute force attacks and password interception. It is often though not always with malicious intent to either copy, modify or destroy data. Intentional corruption of websites can be one of the aims of unauthorized access. 2. Disruption of information systems Different ways exist to disrupt information systems through malicious attacks. One of the best known ways to deny or degrade the services offered by the Internet is a "denial of service" attack. In a way this attack is similar to fax machines being flooded with long and repeated messages. Denial of service attacks attempt to overload web servers or Internet Service Providers with automatically generated messages. Other types of attacks can include disrupting servers operating the domain name system and attacks directed at "routers". Attacks aimed at disrupting systems have been damaging for certain high profile websites like portals. Companies rely on the availability of their websites for their business and those companies that depend on it for "just in time" supply are particularly vulnerable. 3. Execution of malicious software that modifies or destroys data The most well known type of malicious software is the virus. Infamous examples include the "I Love You" and "Melissa" viruses. About 11 % of European users have caught a virus on their home PC. There are other types of malicious software. Some damage the PC itself, whereas others use the PC to attack other networked components. Some programs often called 'logic bombs' can lie dormant until triggered by some event such as a specific date, at which point they can cause major damage by altering or deleting data. Other programs appear to be genuine, but when opened release a malicious attack often called 'Trojan Horses'. Another type is a program often called a worm that does not infect other programs as a virus, but instead creates copies of itself, which in turn create even more copies and eventually swamp the system. 4. Interception of communications Malicious interception of communications compromises the confidentiality and integrity requirements of users. It is often called "sniffing". 5. Malicious misrepresentation Information systems offer new opportunities for misrepresentation and fraud. The taking of someone else's identity on the Internet, and using this for malicious purposes, is often called "spoofing". 12.3.3 Main Technological Skills to Prevent from Hacker If you're worried about viruses or hackers wreaking havoc on your system, take some precautionary measures-and breathe a little easier. The best way to make sure your computer is ready to do battle with its many potential enemies is to load it up with software designed to protect it from potential hackers and evil viruses. Think of your computer as an extension of yourself: You don't run into the street without looking both ways and you don't blindly enter crime-ridden areas without taking precautions. Simply put