Here is what mentioned on Emsisoft's site.
Why is it called "Anti-Malware" and not "Antivirus"?
Our analysis lab has determined that classic viruses only make up less than 0.5% of total threats (in 2012). Referring to our product as an "Antivirus" would therefore be wrong by definition. We're perfectionists so we have elected to use the broader term "Malware" when naming our product. "Malware" includes all types of threats, such as viruses (0.5%), rogue security software (0.5%), rootkits (1.0%), adware (2.7%), possible malicious applications (4.1%), worms (4.6%), financial malware & password stealers (5.3%), online gaming password stealers (6.9%), backdoors (13.3%) and trojans (61.3%). Please note that not all "Anti-Malware" products on the market include the same functionality and protection level.
- See more at:
http://www.emsisoft.in/en/software/antimalware/#sthash.AGEJiiow.dpuf