Virus Basics

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Virus Basics

• Bill BrewerWHS CTC
• Joe AlvaradoWHS Tech

2
Agenda

• Virus basics
• What to be concerned about
• Office protection
• Anti-virus messages

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What is a virus?

• A virus is a program that self-replicates
• It is not data
• You can only catch a virus by running a program
• Your computer runs all kinds of programs

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Basic virus terminology

• Virus
• Self-replicating
• Also called a worm
• Trojan Horse
• A program which appears to be valuable but has an
  unexpected consequence

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How viruses get into computers

• The four most common virus infections come from
• File A virus type that infects existing files
  on the computer (40)
• Macro A virus that runs as a macro in a host
  application such as the MS Office applications
  (35)
• VBScript A virus that uses Windows VisualBasic
  Script functionality (10)
• Internet Worm A virus that is primarily
  characterized by its replication across the
  Internet (5)

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Basic virus defense

• Dont open files that you are not expecting
• Many viruses automatically send files without the
  e-mail account owners knowledge.
• Ask the sender to confirm unexpected files.
• Suspect messages that appear more than once in
  your Inbox
• You may receive the same e-mail from a virus
  repeatedly.

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Basic virus defense (cont.)

• Learn file extensions
• Your computer will display both an icon and a
  file extension for files you receive. Open only
  file extensions you know are safe.

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Examples of risky file types

• The following file types should never be opened
• .EXE
• .PIF
• .BAT
• .VBS
• .COM

9
Office protection

• Office files are mostly data with some program
  code
• Office macros are programs, which can be viruses
• Office will prompt you to enable macros
• Enable macros only when you know why office is
  asking

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Outlook file security

• Outlook will automatically block some kinds of
  executable files, but not all
• Do not assume that because the file made it
  through Outlook that it is safe

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Even Safe Files give you warnings
13
Anti-virus warnings

• Follow instructions on the screen when you
  receive a virus warning from Mcafee Antivirus or
  Computer Associates Antivirus
• Most of the time, the virus software will detect
  and prevent the infection.

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Conclusion

• Leave machines on at all times. Computers can be
  logged off but just turn off monitors.
• Thank you