Despite the large efforts made during the development phase to produce fault free system, most of the software implementations still require the testing of entire system. The main problem in the software testing is the automation that could verify the system without manual intervention. Recent work in software testing is related to the automated fault injection by using fault models from repository. This requires a lot of efforts, which adds to the complexity of the system. To solve this issue, this thesis suggests DefectoFix framework. DefectoFix is an interactive defect fix logging tools that contains five components namely Version Control Sysem (VCS), source code files, differencing algorithm, Defect Fix Model (DFM) creation and additional information (project name, class name, file name, revision number, diff model). The proposed differencing algorithm extracts detailed information by detecting differences in source code files. This algorithm performs comparison at sub-tree levels of source code files. The extracted differences with additional information are stored as DFM in repository. DFM(s) can later be used for the automated fault injection process. The validation of DefectoFix framework is performed by a tool developed using Ruby programming language. Our case study confirms that the proposed framework generates a correct DFM and is useful in automated fault injection and software validation activities.