Digital Forensics · DFIR · Study Project

Mobile Device
Forensics

iPhone Investigation
📅 2024 📷 iOS Artifacts · Autopsy · iMazing 🔓 Simulated Study Scenario

Forensic examination of an iPhone in a simulated theft and fraud scenario conducted as a classroom study project. Recovered deleted SMS/iMessage threads, Safari browsing history, geolocation data from Photos EXIF metadata, call logs, and app usage timestamps. Produced an activity timeline with full chain-of-custody documentation per legal admissibility standards — practising the process used in real digital forensics investigations.

iPhone Chain of Custody Evidence Recovery Timeline Analysis Digital Forensics iOS Artifacts
View on GitHub Methodology ↓

Simulated Scenario

This study project was structured around a fictional case scenario provided as part of a digital forensics course exercise. The scenario: an iPhone belonging to a fictional suspect had been seized as potential evidence in a fraud and theft investigation. The device was provided in a classroom/study context with simulated case data pre-loaded to represent a realistic investigation.

CASE REF:   SIM-DFIR-2024-011   [STUDY PROJECT — SIMULATED DATA]
────────────────────────────────────────────────────────────────
DEVICE:     iPhone (model withheld per study guidelines)
            iOS version: 16.x
            Storage: 64 GB

SCENARIO:   Suspect alleged to have used the device to coordinate
            a fraudulent online purchase scheme and a physical
            theft. Case study asks analysts to recover evidence
            of communications, location presence, and financial
            transaction records from the device.

OBJECTIVE:  Perform forensic acquisition, extract and analyse
            relevant iOS artifacts, reconstruct a timeline of
            key events, and produce admissibility-ready
            documentation with hash verification.
────────────────────────────────────────────────────────────────
NOTE: All names, addresses, and identifying details in this
      project are entirely fictional and generated for the
      study exercise. No real personal data was used.

Forensic Methodology

The four-phase forensic process followed in this study project mirrors the methodology used in professional digital forensics: acquire an evidence image without altering the original, preserve integrity through cryptographic hashing, analyse artifacts systematically, and produce structured documentation.

Artifacts Recovered

The following iOS artifact categories were examined during the analysis phase. Each was sourced from a specific SQLite database or file within the iOS backup structure.

Database
SMS / iMessage Threads
Recovered deleted message threads from sms.db. SQLite message table retains rows even after UI deletion until VACUUM runs.
Database
Safari Browsing History
Extracted URLs, visit timestamps, and page titles from History.db. Identified visits to payment and marketplace URLs.
EXIF Metadata
Photos Geolocation
Photos library EXIF data contained GPS coordinates (latitude/longitude) and capture timestamps for photos taken near the alleged incident location.
Database
Call Logs
Extracted from CallHistory.storedata. Recovered incoming, outgoing, and missed calls with timestamps, durations, and contact associations.
Plist / Database
App Usage Timestamps
Screen time data and app usage history from com.apple.ScreenTime databases. Showed active app sessions during the incident window.
Database
Contacts Near Incident Date
AddressBook database (AddressBook.sqlitedb) — recorded creation timestamps for contacts added in the 48-hour window around the alleged incident.

The iOS backup structure stores most user data in SQLite databases organised under a 40-character SHA-1 hash folder naming scheme. Key database paths within a decrypted backup:

# Key SQLite databases within a decrypted iOS backup (relative paths)

HomeDomain/Library/SMS/sms.db
    └── Tables: message, chat, attachment, handle

HomeDomain/Library/Safari/History.db
    └── Tables: history_items, history_visits

HomeDomain/Library/CallHistoryDB/CallHistory.storedata
    └── Tables: ZCALLRECORD

HomeDomain/Library/AddressBook/AddressBook.sqlitedb
    └── Tables: ABPerson, ABMultiValue

CameraRollDomain/Media/DCIM/
    └── .jpg/.heic files — EXIF GPS coordinates embedded

# Hash verification (performed on acquired backup archive)
examiner@forensics-ws:~$ md5sum iphone_backup_SIM-DFIR-2024-011.zip
a3f7d9e1b2c4f8a0e5d7c1b9f3e2d4a6  iphone_backup_SIM-DFIR-2024-011.zip
examiner@forensics-ws:~$ sha256sum iphone_backup_SIM-DFIR-2024-011.zip
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855  iphone_backup_SIM-DFIR-2024-011.zip
[+] Hash recorded on chain-of-custody form at acquisition time. Verified again before analysis.

Chain of Custody

Chain-of-custody documentation ensures that evidence integrity can be demonstrated in legal proceedings. Even in a study scenario, practising this discipline builds the habit of treating digital evidence as legally sensitive from the moment of acquisition. The following table shows the custody log maintained throughout this study project.

Step Action Tool / Method Hash Verified Notes
CoC-01 Device received and photographed Camera (physical documentation) N/A Device placed in Faraday bag prior to acquisition to prevent remote wipe
CoC-02 Full backup acquired iMazing 2.17 MD5 + SHA-256 recorded Encrypted iTunes-format backup; passphrased separately
CoC-03 Original backup archived (read-only) chmod 444 / write-protect Hash matched CoC-02 Original stored; all analysis on working copy
CoC-04 Working copy created for analysis cp (file system) Hash of copy verified Working copy imported into Autopsy project
CoC-05 Artifact extraction complete Autopsy 4.21, iMazing Consistent with CoC-02 No modifications to working copy detected
CoC-06 Report generated and finalised Manual (Word/PDF) Final hash appended to report Report includes exhibit index and hash manifest

Reconstructed Event Timeline

By correlating timestamps from multiple artifact sources, an activity timeline was reconstructed spanning the 72-hour period of interest in the study scenario. All times are in UTC. Entries marked with a highlight indicate key events relevant to the simulated case allegations.

Day -2
09:14 UTC
Contact Created — "Alex M." AddressBook entry for a new contact created. Creation timestamp within 2 minutes of an incoming SMS message thread being initiated with the same number.
Day -2
09:16 UTC
SMS Thread — Coordination Messages (Recovered Deleted) Series of 14 messages recovered from sms.db despite apparent deletion. Content referenced a specific address, a dollar amount ($2,400), and a pickup time — consistent with the study scenario's fraud allegation.
Day -1
14:33 UTC
Safari — Marketplace Browsing History.db records 7 visits to a second-hand marketplace site. Item search queries and item listing page visits noted. URLs recorded as exhibits.
Day 0
11:07 UTC
Photo Captured — EXIF GPS Match to Incident Location Photo taken at 11:07 UTC. EXIF GPS coordinates (lat/lon) geocode to within 50 metres of the address referenced in the recovered SMS messages. Photo timestamp corroborates physical presence at that location.
Day 0
11:22 UTC
Outgoing Call — Duration 3m 41s CallHistory.storedata records an outgoing call to the "Alex M." contact at 11:22 UTC, duration 221 seconds. Placed 15 minutes after the geolocated photo was taken.
Day 0
14:05 UTC
Safari — Payment Portal Visit Browser history shows navigation to a payment processor URL. Page visit duration approximately 4 minutes per history_visits timestamp delta.
Day +1
08:30 UTC
SMS Thread Deleted (Attempted) The sms.db is_read and cache_has_attachments flags consistent with a thread deletion event. However, the underlying message rows persisted in the SQLite database, recoverable via direct table query bypassing the iOS UI deletion.

Tools Used

Autopsy 4.21 iMazing 2.17 DB Browser for SQLite ExifTool Python (sqlite3 module) hashdeep
Autopsy 4.21 — Primary Analysis Platform Open-source digital forensics platform used as the central case management tool. Autopsy's iOS Backup Analyzer module parsed the iTunes backup structure, automatically categorising artifacts by type. Used for timeline view, keyword search across all databases, and HTML evidence report export.
iMazing 2.17 — Backup Acquisition & Human-Readable Extraction Used for non-destructive iPhone backup creation and for browsing Messages, Call History, and Contacts in a human-readable interface. iMazing's export function produced CSV files for each artifact category — imported into Autopsy and cross-referenced against raw SQLite data.
DB Browser for SQLite — Direct Database Examination Used to directly query the sms.db, History.db, and CallHistory.storedata databases. SQL queries allowed filtering by timestamp ranges and identifying soft-deleted rows not surfaced by iMazing's UI.
ExifTool — EXIF / GPS Metadata Extraction Batch-extracted EXIF metadata from all photos in the DCIM directory of the backup. Output CSV included GPSLatitude, GPSLongitude, DateTimeOriginal, and Make/Model fields. GPS coordinates geocoded against mapping services to identify physical locations.

Key Learning Outcomes