Cyber Crime encompasses a broad range of potentially illegal activities. Generally, however, it may be divided into one of two types of categories;

 Crimes that target computer networks or devices directly;
 Crimes facilitated by computer networks or devices, the primary target of which is independent of the computer network or device.
 Examples of crimes that primarily target computer networks or devices would include,

Malware: Malware is software that is designed to infiltrate a computer without the owner’s information. Malware is a malicious code planted on your computer, and it can give the attacker a truly alarming degree of control over your system, network, and data-all without your knowledge!

Malicious code is a set of instructions that runs on your computer and makes your system do something that you do not want it to do. For example, it can delete sensitive configuration files from your hard drive, rendering your computer completely inoperable; infect your computer and use it as a jumping-off point to spread to all of your buddies' computers; and steal files from your machine. Malicious code in the hands of a crafty attacker is indeed powerful. It's becoming even more of a problem because many of the very same factors fueling the evolution of the computer industry are making our systems even more vulnerable to malicious code. Specifically, malicious code writers benefit from the trends toward mixing static data and executable instructions, increasingly homogenous computing environments, unprecedented connectivity, an ever-larger clueless user base, and an unfriendly world. Malware is based on the perceived intent of the creator rather than any particular features. Malware includes Computer Viruses, Worms, Trojan Horses, most Rootkits, Spyware, Dishonest Adware, Crimeware and other Malicious and Unwanted software.

Denial of Service Attacks: A Denial-of-Service Attack (DoS attack) or Distributed Denial-of-Service Attack (DDoS attack) is an attempt to make a computer resource unavailable to its intended users. Although the means to carry out, motives for, and targets of a DoS attack may vary, it generally consists of the concerted efforts of a person or people to prevent an Internet site or service from functioning efficiently or at all, temporarily or indefinitely. Perpetrators of DoS attacks typically target sites or services hosted on high-profile web servers such as banks, credit card payment gateways, and even root name servers.

A denial of service (DoS) attack is an incident in which a user or organization is deprived of the services of a resource they would normally expect to have. In a distributed denial-of-service, large numbers of compromised systems (sometimes called a botnet) attack a single target. Although a DoS attack does not usually result in the theft of information or other security loss, it can cost the target person or company a great deal of time and money. Typically, the loss of service is the inability of a particular network service, such as e-mail, to be available or the temporary loss of all network connectivity and services. A denial of service attack can also destroy programming and files in affected computer systems. In some cases, DoS attacks have forced Web sites accessed by millions of people to temporarily cease operation.

One common method of attack involves saturating the target (victim) machine with external communications requests, such that it cannot respond to legitimate traffic, or responds so slowly as to be rendered effectively unavailable. In general terms, DoS attacks are implemented by either forcing the targeted computer(s) to reset, or consuming its resources so that it can no longer provide its intended service or obstructing the communication media between the intended users and the victim so that they can no longer communicate adequately. Denial-of-service attacks are considered violations of the IAB's Internet proper use policy, and also violate the acceptable use policies of virtually all Internet Service Providers. They also commonly constitute violations of the laws of individual nations.

Computing Viruses: Computing Viruses are the computer programs that can copy itself and infect a computer without the permission or knowledge of the owner. The term "virus" is also commonly but erroneously used to refer to other types of Malware, Adware, and Spyware programs that do not have the reproductive ability. A true virus can only spread from one computer to another when its host is taken to the target computer; for instance because a user sent it over a network or the Internet, or carried it on a removable medium such as a floppy disk, CD, DVD, or USB drive.

Viruses can increase their chances of spreading to other computers by infecting files on a network file system or a file system that is accessed by another computer.
The term "Computer Virus" is sometimes used as a catch-all phrase to include all types of Malware. Malware includes computer viruses, worms, trojan horses, most Rootkits, Spyware, Dishonest Adware, Crimeware, and other Malicious and unwanted software), including True Viruses. Viruses are sometimes confused with computer worms and Trojan Horses, which are technically different.

A worm can exploit security vulnerabilities to spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a program that appears harmless but has a hidden agenda. Worms and Trojans, like viruses, may cause harm to either a computer system's hosted data, functional performance, or networking throughput, when they are executed. Some viruses and other Malware have symptoms noticeable to the computer user, but many are surreptitious.

Most personal computers are now connected to the Internet and to Local Area Networks, facilitating the spread of malicious code. Today's viruses may also take advantage of network services such as the World Wide Web, E-Mail, Instant Messaging, and File Sharing Systems to spread.

Examples of crimes that merely use computer networks or devices would include,
 Cyber Stalking
 Fraud and Identity Theft
 Phishing Scams

Cyber Stalking: “Cyber Stalking” is also known as Cyber Crime/ Cyber Harassment which is rising up day-by-day. Cyber Stalking is a condition where in a person try to track and hunt someone online and try to assault someone’s privacy or some confidential information. It is a kind of annoyance that can be done online and can upset the life of anyone and make them feeling very Scared and Susceptible. A Cyber Stalker looks for various weak points in people and tries to enter in their life by giving many promotions or offers online related to dating, romance, to make friends and even to sell very expensive items at an unbelievable prize in order to start capturing the interest of the people in order to harass them specially girls or women.

Today, in the world of Computer Modernization where everything is available on internet and on the other hand, Cyber Crime is also rising up Day-by-Day which reflects the normal life of the people who have been harassed by the stalkers. Cyber Stalking usually occurs with girls/ women, who are stalked by men, children and also by adult prowler. A cyber stalker does not have to come out of his home in order to find or harass his targets. Stalker also thinks that he cannot be physically contacted in this cyberspace as he is harassing someone through the internet. Also Stalker can be anyone; he could be your own friend, relative or someone who is anonymous to you to whom you never meet with in your life.

Victims, who have been stalked on the internet, are generally those people who are new on the internet or who are not familiar with the internet security. Stalkers try to target those women, children and man who are mostly new internet users or those who can be easily vulnerable. There are many reasons which came into the picture which motivate the Stalkers to do these kinds of activities. Stalkers stalk because of fun/ enjoyment, Egoistic Nature, hatred, fascination for love and sex etc. In order to stop all these Internet crimes which are keep on increasing day-by-day, our Law-Enforcement agencies are becoming more technically strong and they take support from industrial experts as well at times so that they’ll be able to solve the cases which have been registered under Cyber Crime.

Identity Theft: Identity theft, also known as ID theft is a crime in which a criminal obtains key pieces of personal information, such as Social Security or driver's license numbers, in order to pose as someone else. The information can be used to obtain credit, merchandise, and services using the victims’ name. Identity theft can also provide a thief with false credentials for immigration or other applications. One of the biggest problems with identity theft is that very often the crimes committed by the identity theft expert are often attributed to the victim.

There are two main types of identity theft – account takeover and true name theft. Account takeover identity theft refers to the type of situation where an imposter uses the stolen personal information to gain access to the person’s existing accounts. Often the identity thief will use the stolen identity to acquire even more credit products by changing your address so that you never see the credit card bills that the thief runs up.

True name identity theft means that the thief uses personal information to open new accounts. The thief might open a new credit card account, establish cellular phone service, or open a new checking account in order to obtain blank checks. The Internet has made it easier for an identity thief to use the information they've stolen because transactions can be made without any real verification of someone’s identity. All a thief really needs today is a series of correct numbers to complete the crime.
Some types of identity thieves hack into databases to steal personal information.

However this type of thievery is much rarer than the use of old fashioned methods such as scouring the garbage for old receipts or looking over someone’s shoulder while they are doing a financial transaction. You should also be wary of such criminals at the Department of Motor Vehicles or anywhere else where filling out a long application could provide a thief with enough information to inspire an identity theft.

Phishing Scams: Phishing is a scam in which the attacker sends an email purporting to be from a valid financial or E-Commerce provider. The email often uses fear tactics in an effort to entice the intended victim into visiting a fraudulent website. Once on the website, which generally looks and feels much like the valid eCommerce/banking site, the victim is instructed to login to their account and enter sensitive financial information such as their bank PIN number, their Social Security number, mother's maiden name, etc. This information is then surreptitiously sent to the attacker who then uses it to engage in credit card and bank fraud - or outright identity theft. Most of these Phishing emails appear to be quite legitimate.

Phishing is the criminally fraudulent process of attempting to acquire sensitive information such as usernames, passwords and credit card details by masquerading as a trustworthy entity in an electronic communication. Communications purporting to be from popular social web sites, auction sites, online payment processors or IT administrators are commonly used to lure the unsuspecting public. Phishing is typically carried out by e-mail or instant messaging, and it often directs users to enter details at a fake website whose look and feel are almost identical to the legitimate one. Even when using server authentication, it may require tremendous skill to detect that the website is fake. Phishing is an example of social engineering techniques used to fool users, and exploits the poor usability of current web security technologies. Attempts to deal with the growing number of reported Phishing incidents include legislation, user training, public awareness, and technical security measures.