a computer file that was developed by the European Institute for Computer Antivirus Research (EICAR) and Computer Antivirus Research Organization to test the response of computer antivirus programs. Instead of using real malware, which could cause real damage, this test file allows people to test anti-virus software without having to use real malware.
What is an EICAR test string?
https://en.wikipedia.org/wiki/EICAR_test_file
A specific string of text that you can use to test your AV without actually grabbing a virus.