before sending them out to be duplicated and distributed. • If you sell software, please check your master disks for infections  software you receive. distributing it. You should also, of course, run Disinfectant on all new Mac community. Please carefully test all new software before public domain and shareware software have a special responsibility to the • Bulletin board operators and other people who maintain and distribute  WDEF virus for details. recommend deleting the Desktop file if it exists. See the section about the grant the “make changes” privilege on server root directories. We also AppleShare server. To avoid these problems, administrators should never • The WDEF virus can cause serious performance problems if it infects an  backup. • Back up your servers frequently. Run Disinfectant just before each  server. • Check all new software with Disinfectant before installing it on a  discussion in the “Special Features” section. servers once per week. For more details on scanning servers, see the files on the server disk. At Northwestern, we try to check all our the only way to guarantee that Disinfectant will be able to scan all the production and restart it using your Virus Tools or Disk Tools disk. This is are uninfected. For best results, you should take the server out of • Check server disks frequently with Disinfectant to make certain they  when it is possible. write-protected folders, but you should make every attempt to do this own file or folder, it is not always possible to put applications in spread very rapidly. Since some applications insist on writing to their protected by a protection INIT. This is one way in which viruses can will in turn quickly infect any other Macs on the network which are not infection to the application on the server. If it is a popular application, it network which accesses the disk and uses the application might spread the application is in a writable server folder, any infected Mac on the not have the “Make Changes” privilege. On the other hand, if an disks. Viruses cannot infect applications if they are in folders which do • Try to put software in write-protected folders on AppleShare server  the section about the Preferences window for details. • Consider creating a special “virus scanning station” in your lab. See  the application. Distribute printed copies of the Disinfectant manual. against them. Give them copies of Disinfectant and teach them how to use • Educate the people in your organization about viruses and how to protect  have discovered that students love to play with the start-up disks. protection INIT is still installed and active on all your startup disks. We that they are uninfected. Also check to make certain that the Disinfectant • Check all your lab disks frequently with Disinfectant to make certain   • Install the Disinfectant protection INIT on all your lab startup disks.  make certain that their software is free from infection. viruses. People who sell software also have a special responsibility to share Macs, or share a Mac network, is a perfect breeding ground for domain and shareware software. An environment where many people networks, Mac laboratories, Mac bulletin boards, or collections of public The remaining recommendations are for people who manage Mac   are clean. backup. This has the added advantage that it makes certain your backups One strategy which many people use is to do a full scan just before every  every once in a while will detect any such infections. installed, it is possible for a virus to infect your hard drives. Doing a scan start up from a floppy disk which does not have the Disinfectant INIT just to make certain that they are still uninfected. For example, if you You should, however, periodically do a full scan of all your hard drives  protection INIT do its job and trust it. It is also not necessary to scan your hard drives frequently. Let the  before they can spread or cause any damage. as you have the INIT properly installed, it will detect and block viruses to scan all floppy disks before using them. This is a waste of time. As long Macintosh. It is not necessary to scan all new software before using it or For most people, this is all you have to do to protect your personal  offers an update service. anti-viral product instead of Disinfectant. Purchase a product which Disinfectant releases, we recommend that you use a commercial do not have access to a reliable source of information about new against known viruses and makes no attempt to detect new viruses. If you viruses. This is particularly true of Disinfectant, which only protects versions of anti-viral software are very often ineffective against new • Keep your anti-viral software up-to-date. This is very important. Old  • Make periodic backups of your hard drive, at least once per week.  for a virus to infect files on a locked floppy. a copy, and use the copy. Never unlock the original disk. It is impossible new piece of software, immediately lock the disk on which it came, make • Keep original software on locked floppies. Use copies. When you obtain a  a minute to install and it can save you much grief. • If you do nothing else, religiously use the Disinfectant INIT. It only takes  viruses. minutes per week to effectively protect your Macintosh against the known should take the problem seriously. Using Disinfectant, it only takes a few There is no need to panic over the current virus situation. However, you   åRecommendations / /