What is Computer Crime ?

Any crime involving a computer or a network is referred to as Computer Crime - harmful act committed from or against a computer(cyber crime) or network(net crime).

Practically there is no reliable data on the amount of computer crime and the physical/economic loss to victims, mainly because many of these crimes in the digital work of 1 and 0 remain undetected.

Why is it dangerous than terrestrial crime ?
Estimates are that computer crime costs victims in the USA at least US$ 5×10,00,00,000 / year.

Computer Crime differs from terrestrial crimes because they :
- Are easy to learn (hacking is fun)
- Require few resources relative to the potential damage they cause (just one normal computer)
- Can be committed without being physically present (virus over Internet)
- Are not clearly illegal ( denial of service - DOS )

A  DOS attack occurs when an Internet server is flooded with a continuous stream of bogus/irrelative requests for web pages which may or may not exist, thereby denying legitimate users an opportunity to view or download a page and also possibly crashing the web server.

Eg :  The Yahoo website was attacked on 7 Feb 2000 morning which lasted three hours.
During this attack of DOS Yahoo was pinged at the rate of one gigabyte/second.

Types of Computer Crime :

• Data interception - capturing data in transmission
• Data modification - altering, destroying, or erasing data
• Data theft - taking or copying data, regardless of laws or copyright
• Network interference - impeding or preventing the access of others.The most common example is a DOS attack.
• Network sabotage - modification or destruction of a network system
• Unauthorized access - attempting to gain access to a system or data for which you don’t have permission
• Virus dissemination - introducing software that is damaging to systems or data
• Aiding and abetting - enabling computer crime
• Computer related forgery - alteration of data with the intent to represent as authentic information
• Computer related fraud - alteration of data with the intent to derive economic benefit from the misrepresentation

In order to investigate computer crime skills required include:
- Uncovering and understanding the cause and effect of a computer's actions
- Technical understanding of a system and what it does  daily
- Logical thinking
- An open mind with right application of previous knowledge

Detection of Computer Crime is much tougher than terrestrial Crime because 

Computer or electronic evidence is inherently complex and volatile in its own unique way. Electronic evidence is complex because it can be derived from any computing resource, at any level of operation machine language to meta-data and beyond. The evidence can be latent, not visible or active. It is also volatile, because it can be digitally altered or easily destroyed, often without detection. Some evidence may even be time sensitive.As with any other type of evidence, electronic evidence becomes useless when it is mishandled or improperly managed.

Also working on sources of evidence is complicated.( Sources include Hard drives, RAM, Memory cards, Floppy drives, CD-Rom, Keyboard, Any removable media, Printer, Fax, PDA, Digital camera, Copier, Telephone, Voice mail,Database,encrypted or corrupt data)