An analysis done by Cryen researchers looked at 10.3 million Office 365 emails, revealing that 9.3% were unfiltered spam and contained malware and phishing information. While a small percentage was zero-day unknown malware, many common malware signatures were let through. Microsoft’s filtering is based on off the information they hold is databases to whatever I unknown to them is let through the content filters. The article then encourages the use of comprehensive whitelisting within a corporate environment to help mitigate this risk.
https://www.darkreading.com/cloud/office-365-missed-34000-phishing-emails-last-month/d/d-id/1330282
Kevin,
These number help us to be careful with all the emails we receive. I think that emails are the easiest tools most of attackers use to harm other people computers. We are the users who suppose to trained to follow certain steps when we receive emails, we have to make sure that they were sent from a trusted source. In other words, our curiosity shouldn’t be involved in open or not suspicious emails.