今年的全球防毒軟體市佔率大調查，前五名都是免費防毒。
1. 16.3% Microsoft Security Essentials
2. 13.2% avast! Free Antivirus
3. 6.2% Windows Defender
4. 5.0% Avira Free Antivirus (小紅傘收費版反而很少人用)
5. 4.8% AVG Anti-Virus Free Edition
6. 4.6% ESET Smart Security (ESET是用戶最多的收費軟體)
7. 4.2% Malwarebytes Anti-Malware Pro (使用者是拿來當第二防毒輔助)
8. 3.3% AVG Internet Security (AVG收費版用戶比另外兩A多)
9. 3.3% Kaspersky Internet Security (卡巴收費用戶很多)
10. 3.1% Norton Internet Security (肉盾NIS收費用戶也多)
11. 2.8% ESET NOD32 Antivirus
12. 2.7% COMODO Antivirus
13. 2.5% McAfee VirusScan
14. 2.3% Norton 360
15. 2.2% avast! Internet Security
16. 1.9% Symantec Endpoint Protection (肉盾大企業用戶多)
21.7% Other
Worldwide Antivirus Product Market Share
http://tinyurl.com/np7e49g