home *** CD-ROM | disk | FTP | other *** search
- ┌─────────────────────────────┐
- │ VIRUS REPORT │
- │ nVIR │
- └─────────────────────────────┘
-
- Host Machine: Macintosh.
-
- nVIR is a Macintosh virus that has now led to numerous strains,
- including MEV#, AIDS, nFLU, and nVIR A and B.
-
- When you run an application infected with nVIR A or B on a clean
- system, the infection spreads from the application to the system file.
- After rebooting, the infection in turn spreads from the system to other
- applications, as they are run. The effect can be devastating (see
- sidebar).
-
- At first, nVIR A and B only replicate. When the system file is first
- infected, a counter is initialized to 1000. The counter is decremented
- by 1 each time the system is booted, and it is decremented by 2 each time
- an infected application is run.
-
- When the counter reaches 0, nVIR A will sometimes either say "Don't
- Panic" (if MacinTalk is installed in the system folder) or beep (if
- MacinTalk is not installed in the system folder). This will happen on a
- system boot with a probability of 1/16. It will also happen when an
- infected application is launched with a probability of 31/256. In
- addition, when an infected application is launched, nVIR A may say
- "Don't Panic" twice or beep twice, with a probability of 1/256.
-
- When the counter reaches 0, nVIR B will sometimes beep. nVIR B does
- not call MacinTalk. The beep will happen on a system boot with a
- probability of 1/8. A single beep will happen when an infected
- application is launched with a probability of 15/64. A double beep will
- happen when an infected application is launched with a probability of
- 1/64.
-
- It is possible for nVIR A and nVIR B to mate and sexually reproduce,
- resulting in new viruses combining parts of their parents.
-
- For example, if a system is infected with nVIR A, and if an
- application infected with nVIR B is run on that system, part of the nVIR
- B infection in the application is replaced by part of the nVIR A
- infection from the system. The result contains part from each of its
- parents, and behaves like nVIR A.
-
- Similarly, if a system is infected with nVIR B, and if an application
- infected with nVIR A is run on that system, part of the nVIR A infection
- in the application is replaced by part of the nVIR B infection from the
- system. The result is very similar to its sibling described in the
- previous paragraph, except that it has the opposite "sex" - each part is
- from the opposite parent. It behaves like nVIR B.
-
- These offspring are new viruses. If they are taken to a clean system
- they will infect that system, which will in turn infect other
- applications. The descendents are identical to the original offspring.
-
- Incestual matings of these children with each other and with their
- parents produce results that contain various combinations of parts from
- their parents.<Note: This material prepared by John Norstad, Academic
- Computing and Network Services.>
-
-
- ╔════════════════════════════════════════════════════════════════════╗
- ║ This document was adapted from the book "Computer Viruses", ║
- ║ which is copyright and distributed by the National Computer ║
- ║ Security Association. It contains information compiled from ║
- ║ many sources. To the best of our knowledge, all information ║
- ║ presented here is accurate. ║
- ║ ║
- ║ Please send any updates or corrections to the NCSA, Suite 309, ║
- ║ 4401-A Connecticut Ave NW, Washington, DC 20008. Or call our BBS ║
- ║ and upload the information: (202) 364-1304. Or call us voice at ║
- ║ (202) 364-8252. This version was produced May 22, 1990. ║
- ║ ║
- ║ The NCSA is a non-profit organization dedicated to improving ║
- ║ computer security. Membership in the association is just $45 per ║
- ║ year. Copies of the book "Computer Viruses", which provides ║
- ║ detailed information on over 145 viruses, can be obtained from ║
- ║ the NCSA. Member price: $44; non-member price: $55. ║
- ║ ║
- ║ The document is copyright (c) 1990 NCSA. ║
- ║ ║
- ║ This document may be distributed in any format, providing ║
- ║ this message is not removed or altered. ║
- ╚════════════════════════════════════════════════════════════════════╝
-
-