Virus, Trojans & Worms
Virus, Trojans & Worms are the main threat to any computer that has internet access. There are many security programs out there that ask you to pay an annual subscription. Kaspersky, Mcafee and Norton to name a few. These programs are essential to keeping you safe but dont catch everything. If you notice that your computer slows down or your internet browsing becomes very slow, You may have one of the above. DME Computers can run cleaners on your system that find these programs when your security software misses them. A Thorough scan of your computer and clean can make a huge difference in performance. The following information will give you an in depth view of what we are up against.
What is A Computer Virus?
A virus is a program designed to corrupt other programs and alter the way those programs work. The impact of a virus can range from making your computer crash when a certain key or series of keys is pushed, to deleting important files, and to the extreme: possibly rendering your computer inoperable.
Before getting all worked up about viruses, it's important to understand the limitations of a computer virus. Viruses are programs that infect other programs, or files containing macros (a series of commands grouped together to automate a complex series of tasks) such as Microsoft Word files, Microsoft Excel files and executable files. Computer viruses cannot, do not, and will not infect plain text files, such as e-mail messages and Web pages, nor can they infect pictures or chat groups. Virus programmers are getting better at transmitting viruses, some new high tech viruses can exploit the security system of popular e-mail programs and activate and begin replicating without the user even being aware.
The name "virus" is appropriate, because like a biological virus, a computer virus is small, makes copies of itself, and cannot exist without a host. (It's also a catchier name than Parasitic Self-Replicating Program.)
What is a Trojan.
A Trojan Horse Virus is a common yet difficult to remove computer threat. This is a type of virus that attempts to make the user think that it is a beneficial application.
A Trojan Horse virus works by hiding within a set of seemingly useful software programs. Once executed or installed in the system, this type of virus will start infecting other files in the computer.
A Trojan Horse Virus is also usually capable of stealing important information from the user's computer. It will then send this information to Internet servers designated by the developer of the virus. The developer will then be able to gain a level of control over the computer through this Trojan virus. While these things take place, the user will notice that the infected computer has become very slow or unexpected windows pop up without any activity from the user. Later on, this will result to a computer crash.
A Trojan Horse virus can spread in a number of ways. The most common means of infection is through email attachments. The developer of the virus usually uses various spamming techniques in order to distribute the virus to unsuspecting users.
These emails contain attachments. Once the user opens the attachment, the Trojan Horse Virus immediately infects the system and performs the tasks mentioned above.
Another method used by malware developers to spread their Trojan Horse viruses is via chat software such as Yahoo Messenger and Skype. Another method used by this virus in order to infect other machines is through sending copies of itself to the people in the address book of a user whose computer has already been infected by the virus.
The best way to prevent a Trojan Horse Virus from entering and infecting your computer is to never open email attachments or files that have been sent by unknown senders. However, not all files we can receive are guaranteed to be virus-free. With this, a good way of protecting your PC against malicious programs such as this harmful application is to install and update an antivirus program.
A computer worm is a program which copies itself across a network.
A computer worm differs from a computer virus in that a computer worm can run itself. A virus needs a host program to run, and the virus code runs as part of the host program. A computer worm can spread without a host program, although some modern computer worms also use files to hide inside.
Well known examples of the computer worm
The original computer worm was (perhaps accidentally) unleashed on the Internet by Robert Tappan Morris in 1988. The Internet Worm used sendmail, fingerd, and rsh/rexec to spread itself across the Internet.
The SQL Slammer Worm of 2003 used a vulnerability in Microsoft SQL Server 2000 to spread itself across the Internet. The Blaster Worm, also of 2003, used a vulnerability in Microsoft DCOM RPC to spread itself.
The Melissa worm of 1999, the Sobig worms of 2003 and the Mydoom worm of 2004 all spread through e-mail. These worms shared some features of a trojan horse, in that they spread by enticing a user to open an infected e-mail attachment.
Mydoom also attempted to spread itself through the peer-to-peer file sharing application KaZaA. The Mydoom worms attempted a Denial of Service (DoS) attack against SCO and Microsoft.
