Unwittingly Drafted Into a Zombie Army

Q. For the past year, I have been getting virus-laden messages that purport to be undeliverable mail being returned to me. I recently decided to change my account password, and these bounced e-mail messages suddenly stopped. It seems that someone was logging in to my account and using my address to send this e-mail. Have you heard of this kind of spamming?

A. It is possible that your computer was hijacked by someone on the Internet and added to a botnet. A botnet, also called a zombie army, is a group of computers that have been compromised without their owners' awareness and then used to forward spam and viruses.

Computers without adequate firewall protection to shield them from intruders are at risk for induction into one of these zombie armies, as are machines without antivirus and antispyware protection. Intruders can get into unprotected computers and install software that allows them to remotely control the machines to do specific tasks like sending spam.

If you haven't already, you may want to install a firewall program, (Windows XP and Mac OS X include firewalls; ZoneLabs offers its free Zone Alarm firewall for Windows at www.zonelabs.com) and get antivirus and antispyware programs. You may also want to change any other passwords you use with the computer in case those have been exposed, too.

Finding the Author of a Wiki Article

Q. Is it possible to tell who wrote certain articles in the Wikipedia?

A. The Wikipedia, at www.wikipedia.org, is a free online encyclopedia that anyone can edit. Its English edition has more than a million articles.

Wikipedia encourages its contributors to create a free user account on the site and log in when creating and editing articles, but you don't have to have a user account to write for it. You can see who worked on what page by clicking the History tab at the top of each article to see a list of all the revisions and who did them; the History page displays the computer I.P. (Internet Protocol) addresses of nonregistered contributors.

An article's history page lets you compare previous versions of the text so you can see how the article evolved. All Wikipedia users are also urged to correct any errors they see in articles; just click the "Edit this page" link at the top of the article to make changes.

Free Tax Filing for This Year

Q. After completing my tax return with the TurboTax software, I heard that free filing for federal income tax is available under certain conditions. Is it possible to transfer information from my TurboTax program, or do I have to re-enter the information on one of the free programs available online?

A. If you have a gross adjusted income of ,000 or less, you may qualify for the Internal Revenue Service's Free File service. The I.R.S., working with a group of tax software companies called the Free File Alliance, offers free online tax preparation and electronic filing of federal tax returns for the deadline on April 17, which is the first business day after the statutory deadline of April 15.

If you have already completed your tax return in the TurboTax desktop software, you can electronically file your return for .95 with the program. You cannot, however, export the data to the Web-based tax form of one of the companies participating in the Free File program.

The I.R.S. does not handle the tax preparation or electronic filing chores on its own site, but refers you to its partner companies. About 20 companies offer their services as part of Free File, including the online editions of TurboTax from Intuit and TaxCut from H&R Block.

To use the free service, you would have to re-enter the information on the tax site. Each participating company may also have its own criteria for free filing (like age or residence restrictions), and you typically have to pay a small fee to file your state tax returns online.

You can get more information on using Free File, how to use it and how to pick out an online tax service at www.irs.gov/efile. To get the free service, be sure to use one of the links posted on the I.R.S. site instead of going directly to the company's Web page.

Questions about computer-based technology may be sent to QandA @nytimes.com. This weekly column will address questions of general interest, but e-mail and letters cannot be answered individually.

More Topics:
IRS e-file
Covering electronic filing for individual taxpayers and businesses. Also features links to IRS tax forms.

Internal Revenue Service
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