If you are running Symantec or Norton for your anti-virus you need to update your software now and run a full deep scan. Why you ask. Google discovered that due to a security flaw in these products users could pick up an infection by simply receiving an email – no need to open an attachment or click on a link. As Google says “Just emailing a file to a victim or sending them a link to an exploit is enough to trigger it – the victim does not need to open the file or interact with it in any way. Because no interaction is necessary to exploit it, this is a wormable vulnerability with potentially devastating consequences to Norton and Symantec customers.”
More info available here http://www.siliconbeat.com/2016/06/29/google-identifies-major-symantec-flaws-symantec-says-theyre-now-fixed/?source=email