An ISO image of optical media stored in a CDFS format is being analyzed. What type of evidence does this ISO image represent?

• A. Data from a CD copied using Windows
• B. Data from a CD copied using Mac-based system
• C. Data from a DVD copied using Windows system
• D. Data from a CD copied using Linux system

Answer: (A)

CDFS denotes the CD-ROM File System, which is the structure used for CDs and their ISO 9660 contents. An ISO image stored in this format is essentially a sector-by-sector copy of a CD, preserving the disc’s directory tree and file metadata as it existed on the original media. Because CDFS is the Windows-leaning implementation of ISO 9660, this kind of image points to data that originated from a CD copied on a Windows system. It wouldn’t indicate a DVD (which typically uses UDF) or a CD copied on Mac or Linux in a way that would change the filesystem type; those systems would still produce an ISO, but the explicit CDFS labeling ties it to CD-ROM usage, most commonly associated with Windows. Therefore, the evidence type is data from a CD copied using Windows.