Digital ForensicsDisk / File Carving3 steps · 1 min read

Deleted Doesn't Mean Gone

01Start point: evidence.dd (17 KB disk image).

  • What I found: almost all high-entropy noise with no filesystem structure, which is what a wiped or damaged volume looks like.
  • Thinking: when the filesystem is gone, ignore it and carve by file signature.

02Pivot: carving for signatures.

  • What I did: searched the raw bytes for common magic numbers.
  • Result: a ZIP local file header (PK\x03\x04) at offset 12800 (0x3200). Its central directory and end record (PK\x01\x02 / PK\x05\x06) are intact right after, so the archive is complete.
  • It holds one file: confidential_report.txt (484 bytes, deflate).
Signature scan: a complete ZIP at offset 12800
Signature scan: a complete ZIP at offset 12800

03Extraction.

  • What I did: opened the ZIP from that offset with Python's zipfile and read the file.
  • Result: "CLASSIFIED - INTERNAL INCIDENT REPORT, Case Ref: CIRT-2291-ECHO". The report says the Node-7 backup array was wiped at 03:14 UTC, but remnants "survived in unallocated space". The last line is FLAG: PacketCapture{RECOVERED_DOCUMENT}
Extracted confidential_report.txt with the flag
Extracted confidential_report.txt with the flag