Analyzing Slack Space and File System Artifacts

When to Use

• When searching for hidden or residual data in file system slack space
• For analyzing NTFS Master File Table (MFT) entries for deleted file metadata
• When reconstructing file operations from the USN Change Journal
• For detecting Alternate Data Streams (ADS) used to hide data or malware
• During deep forensic analysis requiring examination beyond standard file recovery

Prerequisites

• Forensic disk image with NTFS file system
• The Sleuth Kit (TSK) tools: istat, icat, fls, blkls, blkstat
• MFTECmd (Eric Zimmerman) for MFT parsing
• MFTExplorer for interactive MFT analysis
• Understanding of NTFS structures (MFT, $UsnJrnl, $LogFile, ADS)
• Python with analyzeMFT or mft library for automated parsing

Workflow

Step 1: Identify and Extract NTFS File System Artifacts

# Determine partition layout
mmls /cases/case-2024-001/images/evidence.dd

# Extract key NTFS system files
# $MFT - Master File Table
icat -o 2048 /cases/case-2024-001/images/evidence.dd 0 > /cases/case-2024-001/ntfs/MFT

# $UsnJrnl:$J - USN Change Journal
icat -o 2048 /cases/case-2024-001/images/evidence.dd 62-128 > /cases/case-2024-001/ntfs/UsnJrnl_J

# $LogFile - Transaction log
icat -o 2048 /cases/case-2024-001/images/evidence.dd 2 > /cases/case-2024-001/ntfs/LogFile

# Extract all slack space from the volume
blkls -s -o 2048 /cases/case-2024-001/images/evidence.dd > /cases/case-2024-001/ntfs/slack_space.raw

# Get file system information
fsstat -o 2048 /cases/case-2024-001/images/evidence.dd | tee /cases/case-2024-001/ntfs/fs_info.txt

Step 2: Analyze the Master File Table (MFT)

# Parse MFT with MFTECmd (Eric Zimmerman)
MFTECmd.exe -f "C:\cases\ntfs\MFT" --csv "C:\cases\analysis\" --csvf mft_analysis.csv

# Parse with analyzeMFT (Python)
pip install analyzeMFT

analyzeMFT.py -f /cases/case-2024-001/ntfs/MFT \
   -o /cases/case-2024-001/analysis/mft_analysis.csv \
   -c