2016 saw the death of three major exploit kits, including Nuclear, Angler, Neutrino and Nuclear. Microsoft, SenseCy and Microsoft Malware Protection Center have noticed this sudden drop in exploit kit activity. Cisco’s 2017 Annual Cybersecurity Report: Spam campaigns accounted for 65% of all email traffic in 2016, with spam levels reaching record levels not seen since 2010. Malvertising increased 132% in 2016 and most malvertising attacks redirected users to various types of online scams, malicious file downloads and phishing pages.
Source: https://www.bleepingcomputer.com/news/security/spam-accounts-for-two-thirds-of-all-email-volume-and-its-still-going-up/