Security Strategy

Successful Security Assessment Programs

by Paul Asadoorian
June 11, 2009

Recently I gave a presentation at the “SANS Penetration Testing Summit ” titled "Zen and The Art Of An Internal Penetration Testing Program". This presentation outlines the steps required to create a successful program and perform internal penetration testing. There are several key components that must exist to create a successful program:

  • Getting Management Buy-In - This is the first and most important step. Management must understand the testing strategy and be kept in the loop on the results and remediation. Business units must also be consulted to determine the impact scanning will have on their environment to establish a schedule for scanning. It does not matter what kind of testing you plan to perform, from vulnerability scans with Nessus to full-blown penetration testing, you must get the approval from management.

Black lists, white lists – what lists? How to audit program usage on your network

by Ron Gula
June 3, 2009

How do you know that the software being executed on your network is authorized and acceptable? Many organizations struggle with this concept or ignore it altogether. There are generally four approaches to enabling or preventing software usage:

  • White listing of software - A third party application or very tight operating system configuration settings is used to only enable specific authorized program names. Everything else is denied by default.
  • Black listing of software - A third party application specifically controls what programs cannot be run. Anything not on the list is allowed by default.
  • Ignorance – Some organizations simply do not have the staff, resources, technology or concern to attempt any type of analysis of what software is allowed.
  • Auditing – Using one or more methods, an organization takes no immediate action on software usage, but it does track and analyze what programs are available and in use to help make better policy decisions, to have a more intelligent incident response process and to help IT troubleshoot issues.

Detecting Microsoft Executables Being Served by an Unknown Service with Nessus

by Ron Gula
August 28, 2008

Many different types of malware and botnets require some sort of exploit payload. This payload can be obtained through traditional compromised services such as HTTP, FTP and even TFTP. Payloads can also be delivered by highly customized or proprietary protocols designed by the malware and botnet creators. 

Tenable’s research team has encountered some ports that can't be fingerprinted and appear to start an executable download when they are connected to. This is a tactic that some of the botnets use to infect additional machines.

"But I patched our DNS servers ..."

by Ron Gula
July 25, 2008

The current DNS cache poisoning issue is a great example of a vulnerability that must be tested with both patch auditing as well as network scanning. Nessus is ideally suited to perform both types of   audits. This blog entry discusses the advantages of using an auditing tool like Nessus as compared to pure patch auditing or network scanning.

NAT and DNS Cache Poisoning

Keeping Track of Your Ethernet Addresses

by Ron Gula
June 30, 2008

Tracking the hardware network address of Ethernet devices can be a daunting task for an enterprise network operations group. The ability to track Ethernet (or MAC) addresses can have tremendous value for tracking changes to the network, user activity and access control. This situation can be exacerbated in a dynamic IP address environment.

Safari Windows Detection ... and all That Implies

by Ron Gula
April 8, 2008

Apple recently gave Windows iTunes users the option to download the Safari web browser. This move was criticized by many bloggers and security experts. What we will be discussing in this blog today is detection of the Windows Safari application and also examine how organizations could react to this situation.


Detecting Web Servers with Malicious Javascript

by Ron Gula
January 9, 2008

Recently, Tenable Network Security introduced Nessus plugin #29871 which looks at the content of a web site to see if it is hosting potential hostile javascript code. There have been several recent mass defacements and infections of 1000s of web sites through SQL injection attacks.