Computer Crime

Businesses rely on data stored on computer systems. Lost or damaged data is usually due to human error. Sometimes data is deliberately damaged or stolen. Businesses must protect their data and ensure they can get it back if anything does happen.

Criminal misuse of data

It is often easy to misuse data stored on a computer because:

  • Alterations can be made without leaving a trace;
  • Very large amounts of data can be stored and searched quickly;
  • Data can be instantly transferred to other locations using e-mail and the Internet;
  • Communications links used to connect computer systems together are vulnerable to attack from hackers. Some hackers create aggressive software that can manipulate or destroy computer programs and data
  • Programs can be designed to deliberately cause damage to computer systems. Viruses and logic bombs are examples of such programs


  • People who use their knowledge of computers to break into computer systems.
  • Some just leave harmless messages to show they’ve been there.
  • Some deliberately try to delete files.
  • The Computer Misuse Act which made hacking illegal.


  • A program that can make copies of itself in order to ‘infect’ other computers.
  • Viruses can spread from one computer to another via infected disks, downloaded files and e-mail.
  • Virus scanning software can be used to protect systems.
  • This software can be set up to scan files when they are opened, downloaded from the Internet or copied.
  • Software should be updated regularly.

Logic bombs

  • A set of instructions written in computer code that can be hidden inside other software and set to activate at a particular date and time.
  • Once activated it takes control of a computer and begins damaging files.

Software piracy

  • Software piracy involves making illegal copies of software are made.
  • Copyright law makes this illegal.

Security and integrity of data

Possible dangers include:

  • Natural hazards such as fires, floods or lightning;
  • Human error causing loss or damage to data;
  • Theft of data electronically due to hacking;
  • Physical theft of disks or other computer hardware;
  • Integrity of data is to do with ‘correctness’;
  • Verification and validation check that data is correct

Backup copies

  • Kept so that data can be restored to its original condition.
  • Backups should always be kept in a secure, airtight and heatproof container at a remote location.
  • Backup copies should be made regularly.

Passwords and levels of access

  • Passwords used to restrict access.
  • Some packages allow individual files to be password protected.
  • Some password systems are hierarchical (i.e. different passwords give different levels of access).

Log files

  • Used to help track down people who have stolen or damaged computer data.
  • A log file records every attempt to log on to a computer (successfully or not).


  • Protects data files from being used if they are stolen
  • Data is coded in such a way that it can’t be read unless special decoding or decryption software is used
sign up to revision world banner