Mobile Device Forensics: Trends and Technologies

Introduction:

Mobile phones and tablets have become a treasure trove of personal information and activity logs that can provide critical evidence in criminal investigations, civil litigation, corporate security breaches, and more. Call logs, texts, browsing history, social media, emails, photos, GPS data, and app activity found on smartphones and tablets can reveal timelines, communications, locations, relationships, intent, and other key insights for forensic investigators.

However, recovering this data through mobile forensics poses unique challenges compared to traditional computer forensics. The proprietary operating systems and tight hardware integration on mobiles require advanced tools, techniques, and training to successfully acquire, examine, and analyze evidence from these devices.

In this blog, we’ll explore the essential processes, capabilities, and limitations of mobile forensics, including:

• Methods for extracting data from mobiles
• The types of evidence and artifacts acquired
• How investigators reconstruct activity timelines
• Notable obstacles facing experts in the field
• The skills and software tool sets required

By the end, you’ll understand the critical role mobile forensics plays in modern investigations and how experts systematically recover and analyze evidence from smartphones and tablets.

Acquiring Data from Mobile Devices:

The first step in any mobile forensics investigation is acquiring the raw data from the device. Investigators typically utilize one or more of the following acquisition techniques:

• Logical acquisition: Uses the device’s native backup capabilities and APIs to communicate with the phone or tablet and extract a logical-level copy of available files, apps, etc. Limited and does not recover deleted data.
• File system acquisition: Similar to logical but directly accesses storage at the file system level instead of through APIs. Provides more access but still does not recover deleted content.
• Physical acquisition: Extracts a complete bit-for-bit image of the entire storage medium, including both active and deleted content. Requires advanced methods to bypass security.
• Chip-off: Physically removes flash memory chip(s) from the device and uses specialized tools to read the raw data directly off the chip(s). Used to bypass damaged devices.

Depending on the circumstances, investigators usually use commercial mobile forensic tools such as Oxygen Forensics, Magnet Axiom, Cellebrite, or Elcomsoft to conduct logical, file system, or physical acquisitions. These tools use advanced protocols, brute-force attacks, and automated scripts to extract evidence from locked and encrypted devices. 

Chip-off tools like IDA Pro and RISC-V are used to directly read memory and storage chips from phones and tablets to bypass locks. Micro soldering skills are required for chip removal. Custom firmware and bootloaders can also enable deeper system access on locked mobiles, but need advanced programming skills. 

Once evidence is successfully acquired, investigators create a forensic copy and hash verification before examination.

Key Evidence Recovered:

Some of the most useful types of user and app data extracted from smartphones and tablets includes:

• SMS messages, instant messages, emails – Provide communication records.
• Call logs – Identify contacts and timestamps.
• Web browsing history and searches – Reveal online activities.
• Photos, videos, audio – Media files often have geotags.
• Contacts list and calendar – Show relationships and planned events.
• Location data from GPS, Wi-Fi, cellular – Place the device at key times/locations.
• Installed app data and logs – Show usage and activity.
• System logs and registry – Provide timeline evidence.
• Deleted content recovered via forensic methods.

This data helps investigators piece together a timeline of what the device was used for, where it was located, who the user interacted with, and what activities they engaged in leading up to, during, and after any incident under investigation.

Challenges Unique to Mobile Forensics:

However, recovering these key evidences from mobile devices poses a number of unique challenges:

• Encryption – Modern smartphones encrypt stored data, preventing access if keys can’t be retrieved.
• Limited access – Mobile OS security controls restrict third-party software access.
• Proprietary formats – Closed-source mobile OSes have unique data structures and artifacts.
• App sandboxing – Apps segregate data, complicating standalone recovery.
• Transient artifacts – Crucial system caches quickly get overwritten with normal usage.
• Remote wipe – Device wipe can destroy evidence if enabled.
• Anti-forensics apps – Software to intentionally hide, encrypt, or destroy data.
• Component miniaturization – Chips become harder to access.

Specialized Tools and Skills Required:

To meet these mobile forensic challenges, professionals utilize a variety of specialized tools, techniques, and training:

• Advanced commercial forensic tools like Cellebrite, Oxygen, Magnet Axiom, Elcomsoft, and GrayKey to extract evidence from mobiles.
• Chip removal tools like IDA Pro and RISC-V to directly access memory and storage chips.
• Custom firmware and bootloaders to enable deeper system access.
• Password cracking tools combined with social engineering tricks.
• Manual parsing of database, PLIST, JSON files.
• Virtual machines and emulators to examine mobiles offline.
• Advanced training for mobile OS internals, reverse engineering, anti-forensics, and testimony.

By combining advanced forensic tools, intense training, and strong foundational knowledge, mobile forensics professionals can overcome the challenges posed by constantly evolving mobile technologies.

The Future of Mobile Forensics:

Mobile forensic experts are going to encounter further challenges in the future as the mobiles and tablets evolve.

• Stronger encryption and hardware integration will increase anti-forensics defenses.
• Isolated app environments will complicate evidence extraction.

• Mainstream biometrics and behavior patterns will require new unlocking techniques.
• Paradigm shifts like AR/VR will bring new data types to acquire and analyze.

However, mobile forensics has constantly evolved to meet past challenges like 4G, 5G, app stores, and mobile OS advances. By maintaining comprehensive skill sets and combining human insight with AI-assisted tools, mobile forensics will continue adapting to solve future cases with equal proficiency.

To know more about the tools and techniques used in Mobile Forensics, please refer our next blog https://hawkeyeforensic.com/2024/03/05/mobile-forensic-tools/