Antimalware Evaluation and Testing · Chapter 10 447 Tools & Traps The EICAR Test File It doesn't seem appropriate to write a chapter on evaluation and testing without mentioning a standard malware testing resource. The EICAR test file (usually encountered as eicar.com) is not a virus, but a PC assembler program constructed so that it can be typed in with a plain American Standard Code for Information Interchange (ASCII) editor. If the program is actually executed it displays the text EICAR-STANDARD-ANTIVIRUS-TEST-FILE!. To use the EICAR test string, type or copy/paste the following text into a test file: X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST- + FILE!$H+ H* An article at the EICAR test site explains the EICAR test file: www.eicar.org/ anti_virus_test_file.html. There's some discussion of the use of eicar.com in the alt.comp.virus FAQ, some of which is reproduced here. (Since I wrote this bit I have no compunction about reproducing it.) "The EICAR file isn't an indication of a scanner's efficiency at detecting viruses,