Participants do not have to wait for an updated virus detection file to be installed to be protected.

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Viral signatures are the patterns used to identify a virus within a file.

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The virus spreads when an executable file is transferred from one PC to another.

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Once the .doc file is opened with either Word 97 or Word 2000, the virus is immediately executed if macros are enabled, Hernan said.

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If you respond then the wormbot tries to persuade you to save the file, and it will even say "lol no its not a virus" (sic) if you ask about the possibility of infection.

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Antivirus makers need to know the virus to be able to assign it a signature and make the file detectible to block the download, according to Thakur.

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The virus was spread by e-mail as an "executable" (.exe) file capable of running on Windows 95 and 98 operating systems.

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Millions of these virus transistors could eventually end up in MP3 players or digital cameras, speeding up image capture or file transfer.

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The Virus Bulletin tests try to catch out anti-virus software with a variety of malicious programs including bots and worms known to be spreading online, file infectors, polymorphic and macro viruses.

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