SANS Internet Storm Center - A global cooperative cyber threat / internet security monitor and alert system. Featuring daily handler diaries with summarizing and analyzing new threats to networks and internet security events.

Security alerts, advisories, and alert summaries from ISS.

Vulnerability and Virus Information - Secunia

Fee based security alert service that provides early warning of active attacks.

PatchLink Update Is the leader in Patch Management Software Solutions for Enterprise Network Security. PatchLink Update is fully Internet-based, automated, cross-platform, security patch management software for enterprise wide discovery and deployment of critical updates, patches, hotfixes, service packs and software and resolving security vulnerabilities across operating systems and applications. PatchLink is the #1 Patch Management Software Tool for Enterprise Network Security.

Established in 2003 to protect the nation's Internet infrastructure, US-CERT coordinates defense against and responses to cyber attacks across the nation.

Secure Elements, a leader in enterprise vulnerability management and compliance risk reduction solutions, automates security and patch remediation strategies across the entire enterprise, reducing business risk and IT management costs while improving systems performance and maintaining business continuity. The company rapidly identifies and intelligently responds to complex and diverse security incidents, protecting mission critical and network infrastructure assets from both known and unknown attacks without limiting operational performance. Using real-time threat intelligence data and analysis, Secure Elements provides administrators with optimal security control and visibility across the enterprise. Based in Northern Virginia, Secure Elements serves organizations in the federal government and critical infrastructure markets, as well the Global 1000.

Studies Internet security vulnerabilities, provides incident response services to sites that have been the victims of attack, publishes a variety of security alerts, researches security and survivability in wide-area-networked computing, and develops information to improve site security.

Non-profit enterprise whose mission is to help organizations reduce the risk of business and e-commerce disruptions resulting from inadequate technical security controls.

eVuln.com - Penetration Tests & Security Advisories List