When i was a newbie i really had a hard time to get all this stuff from internet and from many books!So i gathered all this information on this page.It may be helpful to other newbies like me....Computers follow your orders, not your intentions.

Utilities across the world are being hit by an estimated 100 to 500 attacks from hackers and malicious worms every year, disrupting the ability of companies to control critical manufacturing plants, with potentially devastating consequences.In one of the most serious incidents, Russian hackers took control of a gas pipeline for 24 hours by penetrating electronic control systems. In another case, in Australia a disgruntled employee released 250 million tonnes of raw sewage by attacking a waste water control system.

"In a worst-case scenario, if a chemical or petroleum plant were to go up, there would be a risk of loss of life. If people hack into electricity distribution and water systems, there could also be a big impact," said Justin Lowe, principal consultant at PA Consulting.Control devices, which can be accessed over the internet through wireless links or dedicated telephone lines, either for programming or to feed back management data, have left plants much more vulnerable to electronic attack,Manufacturers and control systems suppliers have not been as quick to develop technology such as firewalls, anti-virus systems and intrusion detection systems as other parts of the IT industry, because until now the risks have been less clear.

A hackers' conference in Birmingham last year gave a demonstration of how to hack into the radio frequency control systems used by UK water companies. An earlier US hackers' conference published details of attacks on embedded control systems.

How hackers affect production

* 34 security incidents targetted at process plants were identified between 1995 and 2003
* 50% of incidents caused damage worth more than £556,000
* 41% of the incidents led to loss of production
* 29% of the incidents led to companies losing the ability to monitor or control the plant
* 70% of the attacks after 2001 were from external sources, 5% were internal and 20% accidental
* 36% of external attacks came through the internet, 20% from a remote dial-up modem, 8% from remote wireless, 8% from virtual private networks;and 4% from a trusted third-party connection
* The number of incidents has been increasing sharply since 2000.

An Australian hacker was sentenced to two years in 2001 after his attack on sewage control computers at a Brisbane council led to the release of one million litres of raw sewage into the grounds of the Hyatt Regency Resort.

Vitek Boden, who worked for the company that installed the computers, launched the attack in revenge after being turned down for a job at the council.

Boden used a laptop, a two-way radio and hacking programs to break into the sewage control computers and reprogram the pumps. He was found guilty of 46 counts of computer hacking.