7 Jan 2011

Consequences

Consequences of an infection on your PC
When you realize that your PC has got infected, you will definitely be worried of the consequences that you will have to confront with. After the infection, it decreases the performance of your PC and slow down the functioning on your personal computer. Without the knowledge of the user, there will be multiple web surfing problems, system instability and other issues. This becomes a serious threat to you and incur you a huge loss.

How does it affect your PC?

There are varies ways in which your PC gets affected. You will be the victim of the existing computer viruses or worms and it is self-replicating computer program. It is being designed in order to infect multiple remote computers in an attempt to deliver a destructive payload. Most of the worms target to infected files, slow down the functioning of the PC, tries to steal your personal information or may install dangerous software's such as backdoors or Trojans.
These kind of worms can also affect operating systems running Microsoft Windows. It makes use of E-mail, file sharing networks, instant messenger, online chats and so on. This gradually, infects the files, corrupts installed applications and thus, will be successful in damaging the entire system. Later, it may also modify the essential system of the settings and make it more vulnerable.  Ultimately, like the parasites these worms harm your system to a greater extent.

How to Avoid Getting A Computer Worm

A computer worm is designed to spread from computer to computer without interaction from
The user. You may have heard of Worms like Conficker, Sasser and Blaster. 
To help prevent getting infected by computer worms
You can follow these 5 steps.


1.Keep your firewall turned on at all times.
2.Keep your operating software up-to-date with security updates.
3.Use updated antivirus software from a trusted source.
4.Use strong passwords, especially on your network.
5.Use caution before you open email attachments, click links in emails or before you
accept transfers.

Different types of Computer Worms.

Email Worms
Spreading goes via infected email messages. Any form of attachment or link in an email may contain a link to an infected website. In the first case activation starts when the user clicks on the attachment while in the second case the activation starts when clicking the link in the email.
Known methods to spread are:
- MS Outlook services
- Direct connection to SMTP servers using their own SMTP API
- Windows MAPI functions
This type of worms is known to harvest an infected computer for email addresses from different sources.
- Windows Address Book database [WAB]
- MS Outlook address book
- Files with appropriate extensions will be scanned for email like strings
Be aware that during spreading some worms construct new sender addresses based on possible names combined with common domain names. So, the sender address in the email doesn't need to be the originator of the email.
Instant Messaging Worms
The spreading used is via instant messaging applications by sending links to infected websites to everyone on the local contact list. The only difference between these and email worms is the way chosen to send the links.
Internet Worms
Nasty ones. These ones will scan all available network resources using local operating system services and/or scan the Internet for vulnerable machines. Attempt will be made to connect to these machines and gain full access to them.
Another way is that the worms scan the Internet for machines still open for exploitation i.e. not patched. Data packets or requests will be send which install the worm or a worm downloader. If succeeded the worm will execute and there it goes again!
IRC Worms
Chat channels are the main target and the same infection/spreading method is used as above - sending infected files or links to infected websites. Infected file sending is less effective as the recipient needs to confirm receipt, save the file and open it before infection will take place.
File-sharing Networks Worms
Copies itself into a shared folder, most likely located on the local machine. The worm will place a copy of itself in a shared folder under a harmless name. Now the worm is ready for download via the P2P network and spreading of the infected file will continue.

Why are Computer Worms made?


Many worms that have been created are only designed to spread, and don't attempt to alter the systems they pass through. However, as the Morris worm and Mydoom showed, the network traffic and other unintended effects can often cause major disruption. A "payload" is code designed to do more than spread the worm–it might delete files on a host system (e.g., the ExploreZip worm), encrypt files in a cryptoviral extortion attack, or send documents via e-mail. A very common payload for worms is to install a backdoor in the infected computer to allow the creation of a "zombie" computer under control of the worm author. Networks of such machines are often referred to as botnets and are very commonly used by spam senders for sending junk email or to cloak their website's address. Spammers are therefore thought to be a source of funding for the creation of such worms, and the worm writers have been caught selling lists of IP addresses of infected machines. Others try to blackmail companies with threatened DoS attacks.

How to Get rid of a computer worm ?

Once Computer worm appears on your computer, you should pay high attention to get rid of it quickly. The best way to remove Computer worm and other Trojans, spyware threats that have sneaked into your computer, you are kindly suggested to use a truly reliable antispyware program. Here, I would like to recommend Spyware
Cease, and most importantly it has been proved to be very effective in removing Computer worm and many other spyware, malware and so on. What's more, you can always get dedicated technical support from its support team whenever you contact them for a spyware problem.

Do you have Computer worm?

If you have enough time and expertise, you can search your computer for Computer worm manually. However, it might take hours to find out all files of Computer worm, and it is possible that Computer worm will appear after rebooting, for its hidden files may still be there

The Good Computer worms

Beginning with the very first research into worms at Xerox PARC, there have been attempts to create useful worms. The Nachi family of worms, for example, tried to download and install patches from Microsoft's website to fix vulnerabilities in the host system–by exploiting those same vulnerabilities. In practice, although this may have made these systems more secure, it generated considerable network traffic, rebooted the machine in the course of patching it, and did its work without the consent of the computer's owner or user.
Some worms, such as XSS worms, have been written for research to determine the factors of how worms spread, such as social activity and change in user behaviour, while other worms are little more than a prank, such as one that sends the popular image macro of an owl with the phrase "O RLY?" to a print queue in the infected computer. Another research proposed what seems to be the first computer worm that operates on the second layer of the OSI model (Data link Layer), it utilizes topology information such as Content-addressable memory (CAM) tables and Spanning Tree information stored in switches to propagate and probe for vulnerable nodes until the enterprise network is covered.

The History of the Computer Worm

 
The actual term "worm"' was first used in John Brunner's 1975 novel, The Shockwave Rider. In that novel, Nichlas Haflinger designs and sets off a data-gathering worm in an act of revenge against the powerful men who run a national electronic information web that induces mass conformity. "You have the biggest-ever worm loose in the net, and it automatically sabotages any attempt to monitor it... There's never been a worm with that tough a head or that long a tail!"
On November 2, 1988, Robert Tappan Morris, a Cornell University computer science graduate student, unleashed what became known as the Morris worm, disrupting perhaps 10% of the computers then on the Internet and prompting the formation of the CERT Coordination Centre  and Phage mailing list Morris himself became the first person tried and convicted under the 1986 Computer Fraud and Abuse Act.

A Definition of the Computer Worm

A computer worm is a malicious program that can replicate and run itself. It differs from a computer virus in that it doesn’t need to embed itself into a host program to run. Computer worms usually spread through networks, although other methods of transport can be utilized such as local drives.
Definition from About.com

Worms - A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating from there, as well.
Definition from Howstuffworks.com

Computer Worms