• by Ray Schultz , November 3, 2017

Microsoft Office 365 missed almost one million spam or malicious messages last month, according to an analysis by email security firm Cyren.

These messages, also called “false negatives,” should not have been delivered to user mailboxes, Cyren says. They constituted a 9.3% “miss” rate.

Overall, Cyren analyzed 10.7 million emails forwarded by Microsoft Office 365 to user inboxes in September.

Rounding them off,  9.7 million were “clean” emails, 960,000 were spam messages, 34,000 were phishing emails and 4,000 were malware emails.

Cyren defines spam as “unsolicited bulk email, usually identified by content scanning techniques or by sophisticated pattern detection applied to elements of the email itself and email distribution patterns.”

Of the legitimate emails, 4.6 million were newsletters, with nearly half of that traffic. 

The phishing emails included 18,000 financial, 5,000 password and 11,000 other attacks.

The malware emails included 2,500 known malware attempts. These included but were not limited to ransomware, key loggers, rootkits, trojans, viruses, and worms,” Cyren says.  

Also slipping through were 1,400 zero-day malware attacks, described by Cyren as new malware with “no previously known malware signature.”

Cyren, through its Email Security Gap Analysis, helps companies determine if their security infrastructure or hosted email service is potentially delivering unwanted or dangerous emails, the company says.