How secure is your enterprise network? Today that's a harder question to answer than ever, especially as enterprise networks continue to grow in size and complexity.

Just consider: the number of security incidents is mushrooming each year, "critical" software patches are issued every month, and attacks move with such speed that companies scarcely have time to respond to them. This summer's Blaster worm, for example, arrived just 26 days after Microsoft disclosed an RPC DCOM Windows flaw and released a patch. That's why knowing the ins and outs of your network infrastructure has never been more mission-critical than it is now.

For many enterprises, providing a "deep look" into the network is the job of a vulnerability assessment scanner. This tool can root out possible weak points in a network before attackers do. For example, a scanner can probe networks for known vulnerabilities in operating systems, applications, and passwords, to name just a few areas. A scanner can also use sophisticated path analysis to illustrate the exact sequence of steps an intruder might take to discover and exploit a vulnerability in the network.


Let's look at the key features of a vulnerability assessment scanner and how to get the most out of this essential tool.

'What can a hacker see?'

Until a few years ago, many businesses were generally safe from Internet intrusions because they relied on dial-up connections. (Dial-up connections via phone lines receive a different Internet address on every call and are open too briefly to give hackers reliable access.) But today's broadband connections have Internet addresses that remain the same either permanently or for hours at a time. Once hackers find their way into a vulnerable network, they can explore or damage it at their leisure. Keep in mind, too, that your network may not be the real object of a hacker's plans. Distributed denial of service attacks have been launched from innocent third-party networks that were hijacked by hackers using clandestine intrusion attacks.