Just a named text file, "AVTest.txt". But also created other new text files with only EICAR string in it. On the other machines with different AV products installed these were detected immediately. On my Avast test station, the file just sits there on the desktop until it is eventually scanned during a system scan. I have opened it, copied it, moved it, etc. and it does not get detected until directly scanned manually or during a system scan.