Some body can do access in to the computer systems or Networks activity for which he is not authorized to do so. This is commonly known as hack
Theft of information contained in electronic form:
By this crime, some body gets access in to the computer systems or Networks activity of another person. Then he collects information stored in computer hard disks and removes the information. This is called Theft of information contained in electronic form.
E-mail bombing occurs when a large number of emails sent to the victim’s computer. As a consequence the victim’s email account or mail servers might crash.
This kind of attack involves altering the raw data just before it is processed by a computer and then changing it back after the processing is completed
Salami attack is one kind of financial crime. Here the computer program is altered. The alteration is so insignificant that in a single case it remains completely unnoticed e.g. A bank employee inserts a program into bank’s servers that deducts a small amount from the account of every customer.
Denial of service Attack :
The computer resource receives so many requests which it can not handle . This crashes the computer resource. As a result the computer resource denies giving proper service to the authorized users. Another kind of denial of service attack is known as Distributed
Denial of Service(DDOS) attack. Here the perpetrators are many. They are geographically widespread.
Virus attack: v
iruses are one kind of programs that attach themselves to a computer or a computer file and then they circulate themselves to other files and to other computers on a network . They usually affect the data on a computer either by altering or deleting it.
Worms are unlike viruses. It does not need the host to attach them. They make functional copies of themselves. They do this repeatedly till they eat up all the available space on a computer’s memory.
These are event dependent programs. These programs are created to do something only when a certain event occurs. Some viruses may be termed logic bombs because they lie dormant all through the year and become active only on a particular date(Like Chernobyl virus).
Trojan attack :
It is an unauthorized program which functions from inside of a computer. It conceals what it is actually doing .There are many simple ways of installing a Trojan in someone’s computer.
Internet Time Theft:
It is a kind of cyber crime. Here an unauthorized person uses internet hours but payment made by another person. It is a theft of internet hours by using log in name & password from various places causing wrongful loss of internet hour of other users.
Web jacking :
It occurs when someone forcefully takes control of a website by cracking the password. After that he changes it. The actual owner of the website does not have any more control over his website. He does not know what appears on that website.
Theft of computer system: It is a kind of offence which involves the theft of a computer, some parts of computer or a peripheral attachment to the computer.
Physically damaging a computer system: It is a crime that is committed by physically damaging a computer or its peripherals.