Phase 3: System & Disk Forensics

Phase 3: System & Disk Forensics

CLI equivalents of EnCase, FTK, and commercial forensic suites. The Sleuth Kit (TSK) provides the same forensic primitives — disk imaging, file system analysis, timeline reconstruction, deleted file recovery — entirely from the terminal.

Forensic Imaging

# Bit-for-bit disk image with progress and hashing
dc3dd if=/dev/sda of=evidence.dd hash=sha256 log=imaging.log

# Create E01 (EnCase format) image
ewfacquire /dev/sda -t evidence -C "Case 2026-001" -D "Subject laptop SSD" -e "Examiner" -E "Case notes"

# Verify E01 integrity
ewfverify evidence.E01

# Inspect E01 metadata
ewfinfo evidence.E01

# Mount E01 as read-only for analysis
ewfmount evidence.E01 /mnt/evidence

Partition & Filesystem Analysis

# List partitions in image
mmls evidence.dd

# Filesystem details (type, block size, inode count)
fsstat -o 2048 evidence.dd

# Volume system info
img_stat evidence.dd

File Listing & Recovery

# List all files (including deleted — marked with *)
fls -r -o 2048 evidence.dd

# List deleted files only
fls -r -d -o 2048 evidence.dd

# Extract file by inode
icat -o 2048 evidence.dd 12345 > recovered_file.pdf

# Inode details (timestamps, size, block pointers)
istat -o 2048 evidence.dd 12345

# Extract raw data blocks
blkcat -o 2048 evidence.dd 500 > raw_block.bin

Timeline Analysis

This is the killer feature — what EnCase charges thousands for.

# Step 1: Generate body file (TSK mactime format)
fls -r -m "/" -o 2048 evidence.dd > body.txt

# Step 2: Create human-readable timeline
mactime -b body.txt -d > timeline.csv

# Step 3: Filter timeline to date range of interest
mactime -b body.txt 2026-03-01..2026-03-15

# Step 4: Analyze with awk — find files modified during incident window
awk -F'|' '$2 >= "2026-03-10" && $2 <= "2026-03-12" {print $2, $NF}' timeline.csv

# Combine with file type analysis
mactime -b body.txt 2026-03-01..2026-03-15 | awk '/\.exe|\.dll|\.ps1/{print}'

File Carving (Deleted File Recovery)

# PhotoRec — interactive carving from disk/image
photorec evidence.dd

# Foremost — header/footer based carving
foremost -t pdf,jpg,png,doc -i evidence.dd -o /output/carved/

# Scalpel — configurable carving (edit scalpel.conf for custom signatures)
scalpel -c /etc/scalpel/scalpel.conf -o /output/carved/ evidence.dd

# Bulk extractor — extract artifacts (emails, URLs, credit cards, GPS)
bulk_extractor -o /output/bulk/ evidence.dd

Hash Analysis

# Generate hash set for known files
find /path -type f -exec sha256sum {} \; > known_hashes.txt

# Compare against NSRL (National Software Reference Library)
hfind -i nsrl-sha1 /path/to/nsrl/NSRLFile.txt <hash>

# Recursive integrity check
hashdeep -r -c sha256 /evidence/ > baseline.txt
hashdeep -r -c sha256 -a -k baseline.txt /evidence/  # audit mode

# Find files matching known-bad hashes
while read hash file; do
  grep -q "$hash" known_bad.txt && echo "MATCH: $file"
done < evidence_hashes.txt
# Find JPEG signatures in raw disk
sigfind -b 512 0xFFD8FFE0 evidence.dd

# Sort files by category using TSK sorter
sorter -d /output/sorted/ -o 2048 evidence.dd

# String extraction from binary/disk
strings -a -n 8 evidence.dd | grep -i "password\|secret\|key"

# Hex analysis of specific offset
xxd -s 0x1000 -l 512 evidence.dd

EnCase Feature Mapping

EnCase Feature CLI Equivalent Notes

Acquire Evidence

dc3dd, ewfacquire

E01 format supported via libewf

Evidence Processor

fls + sorter + bulk_extractor

Parallel with xargs -P

File System Browser

fls -r

Pipe to less or tree-format with awk

Timeline

fls -m + mactime

CSV output — grep, awk, sort

Deleted File Recovery

icat by inode

More precise than EnCase point-and-click

File Carving

photorec, scalpel, foremost

Configurable signatures

Hash Analysis

hfind + NSRL

Same database, CLI access

Keyword Search

strings + grep

bulk_extractor for structured extraction

Bookmarks / Tags

filesystem + notes

Use directory structure + metadata files

Reporting

awk + pandoc

Generate from pipeline output