This article is from the Mini-FAQ: alt.comp.virus FAQ, by George Wenzel gwenzel@telusplanet.net with numerous contributions by others.
Most reputable anti-virus packages will now trigger an
alert if they scan a file beginning with the following text:
X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*
To make this file, copy the above text string into a text file using
the DOS edit program or Windows Notepad, and save it with a .com extension.
Virtually all Windows anti-virus programs and commercial Macintosh
anti-virus programs can recognise this test file. Running the file
displays the text "EICAR-STANDARD-ANTIVIRUS-TEST-FILE!". Most people
in the anti-virus community consider "virus simulators" unnecessary
and unsuitable for testing proper installation of anti-virus products.
 
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