________________________________________________________________ THE COMPUTER INCIDENT ADVISORY CAPABILITY CIAC ADVISORY NOTICE ________________________________________________________________ The nVIR virus has recently infected significant numbers of Macintosh systems at several DOE sites. There are different strains of this virus. Each strain causes somewhat different symptoms such as printing errors on laser printers, slow system response time, or unpredictable system crashes. The exact mechanisms by which nVIR spreads have recently been determined. Removable media (e.g., disks) are the primary means by which nVIR spreads. Thus, if a disk used in an infected Macintosh is removed and inserted in a second Macintosh, the other machine will become infected if any application on that disk is executed in the second machine. In addition, any method used to transfer programs between Macintoshes will spread the nVIR virus. This includes transfer via shareware over a network. However, nVIR cannot spread via a print network's hardware. nVIR is initially difficult to detect. It spreads quickly and frequently affects backups before eradication procedures can be initiated. Disks brought in from off-site are the most common source of nVIR infections. Unauthorized copies of commercial software brought from off-site or exchanged within a site also present a substantial risk of nVIR infection. Vendor demonstration programs are another suspected source of the nVIR virus. We urge you first of all to review your site's policy on sharing disks and using and distributing non-licensed software. Another essential damage prevention measure is to have good anti-viral software available at your site. CIAC recommends that you test any suspect disk with Disinfectant 1.2, a freeware package which also eradicates viruses. Virus Detective, a shareware package, also tests disks to see if they are clean of nVIR and several other viruses. Although it is tedious to use, Gatekeeper, another shareware program, will provide several protection mechanisms. It is important to educate users about the importance of using only software from trusted sources to reduce the possibility of virus infections. Finally, CIAC recommends that your site uses dedicated machines for on-site vendor demonstrations. For further information or to obtain copies of Disinfectant, Virus Detective and/or Gatekeeper, contact CIAC at (415) 422-8193 or (FTS) 532-8193. CIAC's e-mail address is: CIAC@tiger.llnl.gov