Market Samurai is safe to install, it runs on the Adobe Air runtime environment - it's probably prompting you to install or update that.
Market Samurai is software created by a very reputable Australian company which is the gun when it comes to SEO, they have incorporated their knowledge of good SEO practice into this awesome software.
Even better are the
Free Training Videos which will teach you alot about keyword research and the various modules the software provides you with.
The videos are tailored to mainstream, there are settings in Market Samurai which required tweaking for adult use, if anyone wants to learn how to best leverage the software for adult let me know, I am considering running a course on using
Market Samurai in an adult setting.