New computer viruses are being created, exposed and fought every day. These computer viruses are created often just to annoy us and to wreak havoc in our computer systems. Below, I have described ten viruses currently cited as being the most prevalent and being potentially able to inflict the most damage. However, new viruses are being developed daily, so this list is by no means complete. The best thing you can do is stay vigilant, keep your anti-virus software updated, and keep abreast of the current computer virus threats.

Virus: Trojan.Lodear: A Trojan (from Trojan Horse) that tries to download files from a remote source. It will introduce a .dll file into the EXPLORER.EXE process causing system instability.

Virus: W32.Beagle.CO@mm: A mass-mailing worm that lowers security settings. It can delete security-related registry sub keys and may prevent admittance to security-related websites.

Virus: Backdoor.Zagaban: A Trojan that allows the infected computer to be operated as a covert proxy and which may degrade network performance.

Virus: W32/Netsky-P: A mass-mailing worm which spreads by emailing itself to addresses harvested from files on the local drives.

Virus: W32/Mytob-GH: A mass-mailing worm and IRC backdoor Trojan for the Windows platform. Messages sent by this worm will have the subject chosen randomly from a list including titles such as: Notice of account limitation, Email Account Suspension, Security measures, Members Support, Important Notification.

Virus: W32/Mytob-EX: A mass-mailing worm and IRC backdoor Trojan similar in nature to W32-Mytob-GH. W32/Mytob- EX runs continuously in the background, providing a backdoor server which allows a remote hacker to gain admittance and control over your computer via IRC channels. This virus spreads by sending itself to email attachments gleaned from your email address book.

Virus: W32/Mytob-AS, Mytob-BE, Mytob-C, and Mytob-ER: This family of worm variations has similar characteristics in terms of what they are able to do. They are mass-mailing worms with backdoor functionality that can be controlled through the Internet Relay Chat (IRC) network. Furthermore, they can spread themselves through email and through various operating system weaknesses such as the LSASS (MS04-011).

Virus: Zafi-D: A mass-mailing worm and a peer-to-peer worm which copies itself to the Windows system folder with the filename Norton Update.exe. It can then create a number of files in the Windows system folder with filenames made up of 8 random characters and a DLL extension. W32/Zafi-D replicates itself to folders with names containing words like ‘share’, ‘upload’, or ‘music’ as ‘ICQ 2005a new!.exe’ or ‘winamp 5.7 new!.exe’. W32/Zafi-D will also show a fake error message box with the caption “CRC: 04F6Bh” and the text “Error in packed file!”.

Virus: W32/Netsky-D: A mass-mailing worm with IRC backdoor functionality which can also contaminate computers vulnerable to the LSASS (MS04-011) exploit.

Virus: W32/Zafi-B: A peer-to-peer (P2P) and email worm that will reproduce itself to the Windows system folder as a randomly named EXE file. This worm will test for the presence of an Internet connection by attempting to connect to google.com or microsoft.com. A bilingual, worm with an attached Hungarian political text message box which translates to ?We demand that the government accommodates the homeless, tightens up the penal code and VOTES FOR THE DEATH PENALTY to cut down the increasing crime. Jun. 2004, P?cs (SNAF Team)?

Owen Jones, the author of this article, writes on many subjects, but is currently involved with the network antivirus software. If you have an interest in such software, please go over to our website now at Computer Antivirus Software