Simply go this sites and read :
http://www.microsoft.com/security/pypc.aspx | Microsoft
http://www.viruslist.com/ | Kaspersky
http://www.sophos.com/sophos/docs/eng/sophos-a-to-z.pdf | Sophos
Infowar Blogosphere lists by Dancho Danchev
Code:
Anti-Malware Engineering Team
Anti-Virus Rants
Anton Chuvakin
Arbor Network's Blog
BoingBoing
CERIAS
Chinese Hacking Community
Counterterrorism Blog
Darknet Hackers
DefenseTech
Determina Security Blog
Errata Security
Exploit Prevention Labs
F-Secure Labs Blog
FAS on Secrecy
FAS Strategic Security Blog
Fergie's Tech Blog
Finjan's MCRC Blog
Frequency X Blog
GNUCitizen's Blog
Honeyblog
Internet Anthropologist T.T.
Internet Haganah
Internet Storm Center
Jeremiah Grossman
Jihad Watch
Kaspersky Labs Blog
Lance Spitzner
McAfee Avert Labs Blog
Mike Davis
PandaSecurity Labs
Prevx's Blog
Richard Bejtlich's TaoSecurity
RSA's Security Blog
Russian Business Network
Ryan Naraine's Security Watch
ScanSafe's Blog
Secure Works Labs
Sophos Labs Blog
SpywareGuide Greynets Blog
Sunbelt Labs
Symantec Security Response
The Black Flag
The Jawa Report
Threat Level
Trend Micro Labs
UK Honeynet Project's Blog
Web Application Security Labs
WebSense labs
Wired's Danger Room
ZDNet's Zero Day