Please help!

I went onto Outlook, clicked on a non-suspicious message from a sender I know and safari automatically downloaded something named "silent" and I am quite worried right now. I right-clicked, pressed "get info" and it said something to do with skype and outlook but I didn't get a chance to copy it because I deleted and emptied trash straight away.

Does anyone know what this is? I do not have an anit-virus protection either, which is what's worrying me even more. The file was simply "silent" with nothing after it.

Thank you!