During this project we researched if one could use the ideas (and functionalities) of a malicious computer worm for good tasks. This required knowledge about malicious worms and their functionalities - but also the security holes they exploit. We constructed a prototype of a good worm, which spreads over the network and exploits a certain security hole to then fix it. Furthermore we concluded that it is possible! The prototype should be seen a template for how to further develop the technology and the way of thinking for producing good worms in working order. In the end we considered and dicussed if the development of the prototype and its functionalities could be done better, and if it has performed what it was made to do - to protect the computer from its malicious conspecifics.