Recomended security scan tool that reports open ports, incomplete configuration and other security related issues in your network.
For security practitioners who assess complex enterprise networks for security flaws and compliance issues, Nessus is the world’s most widely-deployed vulnerability and configuration assessment product. With more than five million downloads to date, Nessus features high-speed discovery, configuration auditing, asset profiling, sensitive data discovery, patch management integration, and vulnerability analysis of your security posture. Nessus scanners may be distributed throughout an entire enterprise, inside DMZs, and across physically separate networks.

http://www.tenable.com/products/nessus/nessus-product-overview

http://www.acunetix.com/vulnerability-scanner/

Audit your website security with Acunetix Web Vulnerability Scanner

As many as 70% of web sites have vulnerabilities that could lead to the theft of sensitive corporate data such as credit card information and customer lists.

Hackers are concentrating their efforts on web-based applications – shopping carts, forms, login pages, dynamic content, etc. Accessible 24/7 from anywhere in the world, insecure web applications provide easy access to backend corporate databases.