What Hamachi does is to allow two computers which are located in different places to exist side-by-side in the same virtual network. From a security perspective the computer on the other end of a Hamachi connection doesn’t have any direct access to your PC. Instead, it has the same type of access that any other PC on your home network would have. In order to access files on your you would have to intentionally set up a Windows share to explicitly allow them access to your files, just like another computer on your home network would need.

On the down side, you do have to make sure that there are not shares in place where you don’t want them to be. It’s often convenient for a home user to not worry about security and to just share everything between all of the computers in the house. After all, the only PCs in the house are his PCs. With Hamachi running there is now, for all intents and purposes, an additional PC (or two or three) in that house, and that additional PC can see everything that the other PCs in the house can see. Running Hamachi doesn’t necessarily mean that your PC is able to be compromised, but it does mean that you’ll have to be vigilant when it comes to the different types of access paths you allow into your computer.