Definition
File carving is a technique of extracting files from a digital storage device such as a hard disk or memory card based on their content instead of their metadata. It is particularly applicable if file system structure is deleted or damaged, where traditional recovery methods are futile.
File carving works like solving a puzzle by identifying and gathering specific patterns from an extensive data set.
File Carving Details
- No metadata needed: While the other recovery techniques involve using metadata such as file tables or directories, file carving relies on the disk’s raw bytes.
- Headers and Footers: Almost all files have specific header and footer signatures. File carving software relies on these signatures to detect and extract files.
- Continuous Data Blocks: File carving usually works on files stored in continuous blocks. If not (e.g., the file is fragmented), the process becomes more complex and may need further analysis to reconstruct the file correctly.
- Uses: File carving is commonly applied in digital forensics, especially when investigating cybercrimes. It is also used to retrieve data where the file system is corrupted.
Limitations
- It may give false positives if random data resembles a file signature.
- It doesn’t work with fragmented files.
- It might result in incomplete files if some parts have been overwritten.
Popular Tools
Some of the most used file-carving software programs are Photorec and Foremost, which are open-source.