The term computer crime denotes the criminal acts that are oriented against the computers and the criminal acts that are made by the computer. This criminal activity often becomes the international activity. The states of European union settled on the definition of the computer crime: illegal, unmoral and unauthorised act that involves
improper use of the data acquired by the computers or changing of the data in them. The computers offer new technology and new methods of doing criminal acts like stealth, sabotage, espionage, abuse or racket.
The most frequent motives are:
1. hate and anger with bosses or ex-bosses,
2. jokes and experiments,
3. ideological reasons and political motives,
4. challenge, ambitions and curiousness,
5. competitor’s fight. The computer underground - this term devotes the activities and the members of the informal and unofficial groups who are interested in information technologies on the edge of the law or behind the law.
The best-known members are the hackers then the spreaders of the viruses, pornography, programs, films and music.
Who is hacker? In the past it was a computer expert on high level. In present he is the man who intrusion to computer networks or systems. The hackers affirm that they are only curious and they don’t harm and damage. The crackers are bad. In present a great problem is a computer virus. It is a program that damages the other programs or changes their function and damages or changes the data in the computer.
The most often types of computer crime are:
1. Attack on a computer , program, data or communication equipment,
2. Unauthorised use of a computer, program, communication equipment, fax and printer for example the falsification of money,
3. Unauthorised access to data, obtaining of secret data about persons, organisations and about their activities,
4. The stealth of software, hardware and data in them,
5. The modification of the programs or the data.
In all cases of computer crime there is very difficult and complicated to detect, make clear and prove this crime and there is only a little success for their solving. It is mainly because the methods and the engine are on very high technical and intellectual level.