it's more than likely the .jar file is malicious, not really much of a reason for someone to send a .jar in a email anyways.
also, the site is some random arabic political site of some sort
i opened it using command prompt and nothing happened. not too sure what to say about this, it could be malicious.
run the scans, you're probably forgeted unless you used a VM or sandbox
also why would you open it using command prompt; might as well have executed it iirc. it's a far safer bet to open it via notepad or something then to pretty much execute it.