what is computer worm

Computer worm

A computer worm is a separate malware computer program that render itself in order to spread to other computers. It often uses a computer network to spread itself, relying on safety failures on the target computer to entry it. It will be  use this machine as a host to scan and infect other computers. When these new worm-invaded computers are controlled, the worm will be  remain to scan and infect other computers using these computers as hosts, and this behavior will be  remain . Computer worms use repetitive methods to copy themselves without host plans and distribute themselves based on the law of growing  growth, thus manage and convey more and more computers in a short time.  Worms almost all the time cause at least some harm to the network, even if only by drain bandwidth, whereas illness almost all the time rotten or change files on a choose  computer.

Many worms are designed only to spread, and do not attempt to change the complex they pass across . even so , as the Morris worm and My doom showed, even these "payload-free" worms can cause great  disarray by increasing network traffic and other unintended recantation .

History

Morris worm source code floppy diskette at the Computer days of last Museum

The really term "worm" was first used in John Brunner's 1975 novel, The Shock wave driver . In the novel, Nichlas Haflinger designs and sets off a data-meeting worm in an act of revenge against the powerful men who run a national automatic details web that induces mass accord . "You have the biggest-ever worm loose in the net, and it robotic sabotages any essay to monitor it. There's never been groval with that tough a head or that long a tail!"

The second ever computer worm was design  to be an anti-virus program . Named gleaner , it was created by Ray Tomlin son to replicate itself across the ARPANET and delete the probing  Creeper program (the first computer worm, 1971).

On November 2, 1988, Robert Tappan Morris, a Cornell  academy computer science graduate freshman , loose what became known as the Morris worm, derange many more  computers then on the Internet, guessed at the time to be one tenth of all those relate . During the Morris appeal action , the U.S. Court of Appeals estimated the cost of delete the worm from each installation at between $200 and $53,000; this work prompted the formation of the CERT Coordination Cente and Phage mailing list  Morris himself became the first person tried and sentence below the 1986 Computer Fraud and Abuse Act.

Features

Computer ailment generally demand a host plans . The virus writes its own code into the host program. When the plans runs, the written virus program is executed first, causing infection and damage. A worm does not demand a host program, as it is an self made program or code chunk. Therefore, it is not restricted by the host program, but can run independently and busily carry out charge .

Exploit attacks

Because a worm is not limited by the host plans , worms can take head of many operating complex balms to carry out hopping attacks. For sample , the "Nimda" virus exploits balms to attack.

Complexity

Some worms are combined with web page scripts, and are hidden in HTML pages using VBScript, ActiveX and other robotic . When a user entry  a web page carry a virus, the virus robotic resides in reminder  and waits to be triggered. There are also some worms that are blend with backdoor plans or Trojan horses, such as "Code Red".

Contagiousness

Worms are more catching than authentic ailment . They not only infect local computers, but also all waiter and clients on the network based on the local computer. Worms can easily spread across shared folders, e-mails, malicious web pages, and waiter with a large digit of blame in the network.