In modern world, the use of digital devices for leisure or professional reasons is growing quickly; nevertheless, criminals try to fool authorities and hide evidence in a computer by changing the file type. File type detection is a very demanding task for a digital forensic examiner. In this paper, a new methodology is proposed -in a digital forensics perspective-to identify altered file types with high accuracy by employing computational intelligence techniques. The proposed methodology is

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... ied to the three most common image file types (jpg, png and gif) as well as to uncompressed tiff images. A three-stage process involving feature extraction (Byte Frequency Distribution), feature selection (genetic algorithm) and classification (neural network) is proposed. Experimental results were conducted having files altered in a digital forensics perspective and the results are presented. The proposed model shows very high and exceptional accuracy in file type identification.