Viruses Worms and Email Attachments

Information from other sites

Beal, V. (2009, April 24) Rogue Anti-Virus Software Explained. Rogue anti-virus programs usually appears in the form of a fake Windows warning on your computer system that reads something like, you have a specific number of viruses on your computer (usually in the hundreds) and that this software has detected those viruses. To get rid of these viruses, you're prompted to buy the full-version of the antivirus software (which is really rogue antivirus software)
http://www.webopedia.com/DidYouKnow/Internet/2009/Rogue_AntiVirus_Software.asp

Firewalls. This site provides good information about firewalls including a review of all the products.
http://www.firewallguide.com/

The Difference Between a Virus, Worm and Trojan Horse? Excellent information from Webopedia.
http://www.webopedia.com/DidYouKnow/Internet/2004/virus.asp

What is a Trojan Horse. Excellent explanation including telltale signs.
http://www.nohack.net/trojans.htm


Viruses/Worms & Email Attachments

In the "good old days" (15 years or more) viruses were generally introduced to computers by an infected disk. The virus was one of two kinds, a program, or a boot sector virus. Program viruses attached themselves to a program, replicated themselves within your computer and did whatever they were programmed to do, which could be as innocuous as putting a one time message on your screen or as malicious as destroying other programs and your files. The second type was a boot virus which infected what is known as the "boot sector" of a diskette, or the place on a disk that the computer reads while "booting up" (starting). You caught a program virus usually from an infected program, which may have been an illicit copy, and a boot virus by having the disk infected with a boot virus in your computer when you turned it on, or "booted it".

Today the most usual type of virus is spread by email or the Web - the social networking sites are also vulnerable. One can quibble over whether to call these menaces trojan horses, worms, or viruses, but the bottom line is that you don't want any of them! One protection against any of these menaces is to be a little paranoid about email attachments and unknown Websites. This is not to say that you should stop sending and receiving email or stop using the Web, but you should exercise some caution. The best caution against email attachments is to never open an email attachment that arrives out of the blue, i.e. you don't have any reason to expect it. Even if it is from someone you know. If you really want to see what is in the attachment and can't contact the sender, save the attachment and have your anti-virus checker scan the file before you open it. This writer has found multiple worms in the current group of .pss (Power Point Shows) currently making the email rounds.

BEWARE, there is a temptation to rely on an anti-virus program and believe that this will protect you against all evil. Anti-virus programs have their place, and this writer has caught many viruses with one, but relying on them to be all protecting is dangerous. First, the anti-virus program only protects you against a virus that it knows. Three to ten new viruses are discovered each day, and it takes time for the anti-virus vendors to include the new ones in their program. Fortunately, most anti-virus programs automatically update themselves - if yours does not you need to make updating almost a daily occurrence.

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Macro Viruses

Although not very common today, some viruses are spread by attaching a small program known as a macro (a macro can be created in most application programs by a user, generally to quickly perform a function that the user performs repeatedly, but when performed using the prescribed steps takes a great deal of time) to a file such as a word processing document. Although macros are useful, because they can be designed to start as soon as a file is open they can create havoc before you know they are operating. You can easily protect yourself against this type of virus. Whenever you open a document that was an email attachment and you are asked if you wish to enable the macro to run, click on DISABLE the macro. Do NOT let the macro run!

Email Viruses Spread By Reading Email

Black hat hackers (the bad guys) find and exploit security holes in operating systems in computers. As soon as security problems are found, the operating system's vendor takes steps to close it and makes updates for the operating system available. The newer systems either update automatically, or tell you that new updates are available and ask you if you wish to download them. A "yes" answer automatically contacts the vendor's site and downloads the update.

Examples of email messages that usually lead to viruses or worms
http://www.michaelhorowitz.com/bademails.html

Clues to Viruses in File Name Extensions

An extension is characters after the dot in a file name. Word files always have ".doc" at the end of their file name and Excel files have ".xls" (Office 2007 files add an x to the extension).

Files that are very dangerous are those whose extensions are ".exe" ".vbs" "pif" "scr" "zip" and ".com." These files are what is known as an executable file, that is, they are programs. (If your computer does not show extensions, this can be changed.) If a file with such an extension arrives in your email, be alert that this can be trouble. Under no circumstance open one until you have checked it with an updated anti-virus checker, and even then think twice before opening. As you make a decision ask yourself, "Do I really need this file?" Even if I am assured the file is ok, I will not open any file sent as an attachment with the aforementioned extensions.

Please note that although many viruses today are found by your anti-virus checker before you see the offending file, there is often a problem scanning a zip file. Before unzipping, scan it with your anti-virus checker and then scan again each file after unzipping.

Another word to the wise, it is very easy to change the extension of a file by renaming the file so that it looks harmless. Thus, don't rely 100% on these extensions. Scan any remotely questionable file with your virus checker.

To find out what type of file a file extension represents, see the comprehensive list of extensions at Webopedia's Data Format and File Extensions.

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Anti-Virus Programs

Even though their protection is not 100%, if you are on the Internet at all it is necessary to obtain, install, and keep updated (Good ones will automatically update if you allow it), a good anti-virus program. They offer some protection from viruses you might pick up on the Web as well as checking many attachments (but not all) that you choose to open. These programs can be downloaded from the web or purchased in a software store. Many new computers today come with trial copies of anti-virus products.

Chain Letters and Other Non-Viral Computer Hoaxes

The quickness with which information can spread on the Internet encourages some to take advantage of this. Unsubstantiated rumors can easily be spread by the Internet. Thus, take with a grain of salt anything that stretches your credibility, especially those messages with no source that one can check. Also be wary of those that give a source - every time I check such a source I find that it is phony. Unfortunately, there are many damaging rumors circulating on the Internet - from both sides of the political spectrum. If you can't verify the information in a message, don't pass it on - at best it is supposition based on something taken out of context, at worst, downright untrue.

Chain letters are one of the most prevalent of this type of Internet abuse. Incidentally, if you are accessing the Internet through an agency account it is advisable that you refrain from passing on ANY chain letter. Many institutions have policies against chain letters. Penalties range from a warning to losing your account to losing your job.

Chain letters often appear very legitimate and appeal to a desire to do some good. One that makes the rounds routinely asks for a get well card to be sent to a given person who wants to be in the Guinness Book of Records, or it may ask for an email message to be sent to an individual for the same reason. After performing the given deed, you are asked to pass the letter on. You may be promised good health if you pass the letter on, or that something bad will happen if you break the chain.

Or, a chain letter may warn of something such as the Klingerman Virus. This was suppose to be spread by a letter received by email. There was a phone number to call at the end of the letter. Before passing on a warning, check it out at the Snopes site . Besides telling you if a rumor is false, it also verifies those that are true,

A realistic appraisal of some chain letters should identify them immediately as a hoax. If you are asked to send money, or offered a freebie beware. Check with Snopes before you make a decision as to how to react.

If you are tempted to pass on the letter, think ahead to the possible consequences. Sending thousands of get well cards or electronic messages to one individual is going to create a big problem to the recipient. Also, chain letters are used by some to get a list of current email addresses.

Let the rule "Check out anything before you pass it on and be very skeptical" guide you in how you handle chain letters or other Internet received warnings.

 

Email advising of virus file on your computer

An older form of harassment involves sending an you an email that asks if you have a file named "X" (you fill it in) on your computer. It then says that it is a virus and in 14 days will delete all your files. This is followed by elaborate instructions on exactly how to check for the file and how to delete it if you have it.

You have the file. And it is NOT a virus. If you look at file details you will see that the file in question was created the day that your computer was set up. Why? Because it is part of the operating system or a program. Deleting it can cause your computer to work improperly, or more likely not work at all.

Although not currently seen, this could easily resurface in a slightly different manner. Remember, check these out with Snopes!

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Created April 22, 2009

 

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