旼컴컴컴컴컴컴컴컴컴컴컴컴컴컴� � VIRUS REPORT � � 1536 � 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴� Synonyms: Zero Bug. Date of Origin: September, 1989. Place of Origin: the Netherlands. Host Machine: PC compatibles. Host Files: Remains resident. Infects COM files. OnScreen Symptoms: A smiley face character may appear on the screen and "eat" any 0's it can find. Increase in Size of Infected Files: 1536 bytes. Nature of Damage: Affects system run-time operation. Corrupts program or overlay files. Detected by: Scanv38+, F-Prot Removed by: CleanUp, Scan/D, F-Prot, or delete infected files. The Zero Bug virus was first isolated in the Netherlands by Jan Terpstra in September, 1989. This virus is a memory resident .COM file infector. Infected .COM files will increase in size by 1,536 bytes, however the increase in file length will not show up when the disk directory is displayed. The virus's main objective is to infect the copy of COMMAND.COM indicated by the environment variable COMSPEC. If COMSPEC doesn't point to anything, the Zero Bug virus will install itself memory resident using INT 21h. After the virus has either infected COMMAND.COM or become memory resident, it will infect all COM files that are accessed, including those accessed by actions such as COPY or XCOPY. Any COM file created on an infected system will also be infected. If the currently loaded COMMAND.COM is infected, the virus will hook into the timer interrupt 1Ch, and after a certain amount of time has past, a smiley face character (ASCII 01) will appear and eat all the zeros it can find on the screen. The virus does not delete files or format disks in its present form. �袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴� � 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. � 훤袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴袴暠  Downloaded From P-80 International Information Systems 304-744-2253