Virus Information

General advice to prevent virus infections

  1. Do not open any files attached to an email from an unknown, suspicious or untrustworthy source.
  2. Do not open any files attached to an email unless you know what it is, even if it appears to come from a dear friend or someone you know. Some viruses can replicate themselves and spread through email. Better be safe than sorry and confirm that they really sent it.
  3. Do not open any files attached to an email if the subject line is questionable or unexpected. If the need to do so is there always save the file to your hard drive before doing so.
  4. Delete chain emails and junk email. Do not forward or reply to any to them. These types of email are considered spam, which is unsolicited, intrusive mail that clogs up the network.
  5. Do not download any files from strangers.
  6. Exercise caution when downloading files from the Internet. Ensure that the source is a legitimate and reputable one. Verify that an anti-virus program checks the files on the download site. If you're uncertain, don't download the file at all or download the file to a floppy and test it with your own anti-virus software.
  7. Back up your files on a regular basis. If a virus destroys your files, at least you can replace them with your back-up copy. You should store your backup copy in a separate location from your work files, one that is preferably not on your computer.
  8. When in doubt, always error on the side of caution and do not open, download, or execute any files or email attachments. Not executing is the more important of these caveats.


Install antivirus/anti-malware software

NOTE: Viruses spread through internet and local networks. To prevent problems, please make sure that you have virus protection installed. 

At SSIS, we recommend using Avira Antivir Personal Edition, which is free to use for personal, non-commercial purposes. It can be downloaded at

Windows Version

Macintosh Version

Other options are

Sophos Home





The free Personal Edition of Avira Antivir shows one advertisement per day, which can be ignored (click "Ok" at the bottom of the advertisement). Other than that, it is a perfectly capable antivirus, which uses the same protection level as the Professional Edition, and is consistently among the highest ranked antivirus programs in professional comparatives.

What to do if the computer is already infected

If your computer is infected, very often it is impossible to install or download an antivirus program. If you try to open a link in your web browser for downloading an antivirus, many modern viruses will block the browser, or close it immediately. To help in this case, it is a good idea to use an "Antivirus Rescue CD". Fortunately, there are several of these that we can use. Here are links to some of them that are reliable, and provided free of cost.

You will need a blank CD-R/RW/USB and software to use these ISO images to create a bootable disc. Almost all standard CD recording software can process ISO image files. Just in case, here is a video that explains this process using Rufus, a free program for Windows: How to burn ISO image.

Additionally, you can watch these videos for some good advice and suggestions about other programs to use if your computer gets infected.