From itproportal.com
Spam is the number one source of malware as cyber criminals employ new tactics to catch unsuspecting users.
Despite the fact that cyber criminals have become savvier, new research has revealed that sending spam emails is still their preferred way of distributing malware, scams and malicious URLs 40 years after the first spam email was sent.
F-secure and MWR InfoSecurity discovered that cyber criminals are still using spam emails though they have begun to deploy new tricks to deliver better results.
More information here