Approaches for ensuring a digital file does not contain malicious code. A digital file in an original format may or may not contain malicious code. An intermediate copy of the digital file in an intermediate format is created from the digital file in the original format. The intermediate format preserves a visual or audio presentation of the digital file without supporting metadata or file format data structures of the original format. A sterilized copy of the digital file is created from the intermediate copy. The sterilized copy is in the original format. The sterilized copy comprises a digital signature indicating that the sterilized copy has been converted from the intermediate format to the original format. Advantageously, the sterilized copy is guaranteed to not possess any malicious code.