Nessus

Category: Vulnerability Scanners
Website: http://www.nessus.org
Manufacturer: Nessus
Operating System: Unix/Linux (for windows version see NeWT)

Description:
Nessus is a remote security scanner that uses a rules based system for scanning remote systems. Nessus scans everything using small script based plug-ins which makes updating it with the latest vulnerabilities easy. It is open source so new fixes and features are constantly being added.

Strengths:
   · Nessus doesn't assume anything about the network it is scanning, for instance if a HTTP service is running on port 1234 Nessus will discover it and test it for all known HTTP vulnerabilities.
   · Plug-in based testing, small scripted pug-ins allow Nessus to do its job, allowing for quick and easy updates.
   · Can scan local and remote machines.
   · Has SSL support
   · Can perform Non-Destructive or thorough testing.
   · Accurate scanner; Nessus found more vulnerabilities than any other scanner tested by Network Computing magazine

Weaknesses:
   · UI difficult to use
   · Very complex, might take a long time for the sysadmin to figure out how to customize Nessus to accurately scan a complex network.

Target:
Any machine that has a public IP address that a hacker could scan. Public facing servers are the more vulnerable and the likeliest targets.

Mitigation/Recommendation:
The best mitigation is to keep your machines up to date with patches, use the best scanner you can afford to find, purchase a security audit from security professionals, improve you and your staff's security knowledge through training and experience, and be sure to fix any weaknesses apparent on your machines. We recommend Nessus as a good open-source free scanner. The good news is that if you use the scanner first, the hacker who uses a scanner to investigate your defenses will not find anything to attack and may move on to an easier target.

Price:
Free

Penetration (10):
Very High This is the most likely scanner a hacker will use to attack a server. It open source and easy to modify. This is an ideal information gathering and attack planning tool. As the tool will report a huge variety of known vulnerabilities and vulnerability types the damage potential is high. The scanner will paint big bulls-eyes on any weakness left open on any accessible machine. Hackers will commonly use network scanners as a first step to see how secure a network is. Nessus is the #1 tool on the top 75 tools used by hackers list according to insecure.org

Simplicity (4-8):
Skilled to beginner Beginner, the canned scans are easy to run. Results are easy to interpret but in most cases would take moderate skill to create an exploit based on what is learned. Hacker will have to either find a canned exploit and figure out how to deploy to the target or will have to write there own

Damage Potential (6):
This tool comes with a number of known exploits that can cause a server to fail out of the box.