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- ┌─────────────────────────────┐
- │ VIRUS REPORT │
- │ Vacsina │
- └─────────────────────────────┘
-
- Date of Origin: August, 1989.
-
- Place of Origin: Sophia, Bulgaria.
-
- Host Machine: PC compatibles.
-
- Host Files: Remains resident. Infects COM, EXE, SYS, and BIN files.
-
- OnScreen Symptoms: An infected file may beep when executed.
-
- Increase in Size of Infected Files: 1206 bytes.
-
- Nature of Damage: Affects system run-time operation. Corrupts program or
- overlay files.
-
- Detected by: Scanv56+, F-Prot.
-
- Removed by: CleanUp, Scan/D/A, F-Prot, or delete infected files.
-
- Synonym: TP04VIR virus.
-
- Developed in Sophia, Bulgaria, and possibly first reported by
- reported by Chris Fischer in Germany in August, 1989. Vacsina takes over
- interrupt 21 and connects to COM and EXE files. Vacsina works on
- PC/MS-DOS ver. 2.0 or higher. It infects COM files increasing them by
- 1206 to 1221 bytes (placing the virus code on a paragraph start). It
- infects EXE files in two passes: After the first pass the EXE file is 132
- bytes longer; after the second pass its size increases by an aditional
- 1206 to 1221 bytes. The virus installs a TSR in memory wich will infect
- executable files upon loading them (INT 21 subfunction 4B00) using 8208
- bytes of memory.
-
- The only "function" found so far is an audible alarm or beep(BELL
- character) whenever another file is successfully infected. This suggests
- that this virus is a "draft", and more is to come.
-
- Vacsina infects COM files that are bigger than 04B6h bytes and
- smaller than F593h bytes and start with a JMP (E9h). Vacsina infects EXE
- files if they are smaller than FDB3 bytes (no lower limit).
-
- The virus is named<Note: by Torsten Boerstler, Christoph Fischer and
- Rainer Stober of the Micro-BIT Virus Team, University of Karlsruhe, West
- Germany.> "vacsina" because it opens a file named VACSINA. It doesn't
- check the return status of the open call, and never touches the file
- until the end of the virus code, where it closes the file (again ignoring
- the return code). It is believed that vacsina is a prematurely-escaped
- virus (or code built to detect viruses), and that the virus programmer
- will add some code in a later version of the virus.
-
- To detect the original virus, search for the word VACSINA (all
- capitals).
-
-
- ╔════════════════════════════════════════════════════════════════════╗
- ║ 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 ║
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- ║ detailed information on over 145 viruses, can be obtained from ║
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- ║ ║
- ║ The document is copyright (c) 1990 NCSA. ║
- ║ ║
- ║ This document may be distributed in any format, providing ║
- ║ this message is not removed or altered. ║
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