basically what it does, it infects one uninfected file in a directory every time its ran. 5 days or less before 19 september of any year (trollface creation date) it displays a message "epic troll in x days", at 19 it overwrites mbr and you cant run any program, because it only shows "U MAD BRO" and then quits. When you reboot a computer, your mbr is now a program that displays ascii art trollface.
Edit: Oops my bad, september isn't 8th month.