7 essential artifacts for macOS forensics

In the realm of digital forensics, mac forensics (the investigation of macOS systems) present a unique landscape filled with crucial artifacts that can provide deep insights into user activities, system events, and potential security breaches. Whether you’re investigating a criminal case, responding to an insider threat, or managing a cybersecurity incident, understanding these key forensic artifacts is essential.  

Key macOS forensics artifacts 

We are going to examine the top seven digital forensic artifacts for macOS forensics, detailing their locations, what they reveal, and how to interpret them. Each artifact plays a critical role in unraveling the complexities of user interactions and system behaviors, making them indispensable tools in the digital forensic investigator’s toolkit. 

1. User Home Directory 

Location: /Users/username/ 

• Description: The User Home Directory is where user-specific data such as documents, downloads, desktop files, and user-specific configuration files are stored. This includes potentially critical files like .bash_history, .zsh_history, Documents, and Downloads directories. 
• Interpretation: Analyzing files in the User Home Directory can reveal user activity, preferences, and potential malicious downloads. Examining hidden files such as .bash_history can uncover command-line activities, providing insights into scripts or commands executed by the user. 
• From a .zsh_history file we can see the content of the command-line activities for example: 

2. System logs 

• Location: /var/log/ 
• Description: System logs in macOS are comprehensive records of system-level activities. Logs such as system.log, install.log, and appfirewall.log contain valuable data on system operations, software installations, network activities, and potential security events. 
• Interpretation: By analyzing system logs, investigators can track system events, detect unauthorized access attempts, and identify the installation of unauthorized software or malware. For instance, the appfirewall.log helps trace network connections, providing insights into possible data exfiltration. 
• For example, here we see Axiom has parsed and categorized login history from a file located with \private\var\log\: 

3. Safari browsing history 

• Location: ~/Library/Safari/History.db 
• Description: Safari, being the default web browser for macOS, stores browsing history, bookmarks, and downloads in an SQLite database called History.db. 
• Interpretation: The History.db file reveals a timeline of websites visited, search queries, and associated metadata. Investigators can use this data to reconstruct user online behavior, potentially uncovering visits to illicit or unauthorized sites. 

4. Keychain 

• Location: ~/Library/Keychains/ 
• Description: The Keychain in macOS securely stores passwords, certificates, and other authentication data. It is a crucial artifact for understanding what access the user had. 
• Interpretation: Extracting and decrypting keychain data allows forensic analysts to recover stored passwords, Wi-Fi credentials, and certificates, which can be pivotal in uncovering unauthorized access or confirming user actions on the system. 

5. Time Machine backups 

• Location: Varies (External Drive, Network Location) 
• Description: Time Machine is macOS’s built-in backup feature that regularly backs up the system to an external drive or network location. These backups include user files, system settings, and installed applications. 
• Interpretation: Time Machine backups can be invaluable in recovering deleted files, accessing older versions of documents, and understanding system states at various points in time. They also serve as a record of files that might have been removed or tampered with. 

6. Spotlight database 

• Location: /Volumes/DriveName/.Spotlight-V100/ 
• Description: The Spotlight search tool indexes files and metadata on macOS, storing this data in a hidden database. This database contains information on file paths, creation dates, and content snippets. 
• Interpretation: The Spotlight database can be analyzed to find files of interest based on keywords, locate hidden or obscure files, and track file access times. It is particularly useful in discovering artifacts that may not be immediately visible through regular file system navigation. 

7. Apple Unified Log 

• Location: /var/db/diagnostics/ 
• Description: The Unified Log consolidates logs from various system components into a single, structured logging system. It includes both system-level and application-level logs. 
• Interpretation: The Unified Log provides a detailed, timestamped account of system events, application behavior, and system performance metrics. It is crucial for building a comprehensive timeline of activities, identifying patterns, and detecting anomalies. 
• For example, this change to the AirDrop Discoverability artifact can be seen in /Var/db/diagnostics/ 

Example cases using macOS forensic artifacts 

Criminal investigation: User Home Directory 

A suspect is believed to be involved in distributing illegal material online. Investigators analyze the User Home Directory of the suspect’s macOS device, particularly focusing on the Downloads and Documents folders. They discover files related to illegal content along with evidence in the .zsh_history showing commands used to anonymize the user’s activities online. This evidence is presented in court to confirm the suspect’s involvement in the crime. 

Insider investigation: Keychain 

A company suspects an employee of leaking confidential data. The forensic team extracts the Keychain from the employee’s macOS device and recovers stored passwords and Wi-Fi credentials. By analyzing these, they uncover that the employee accessed a secure internal network without authorization. The analysis shows connections to unauthorized cloud storage services, where sensitive data was uploaded. This evidence leads to disciplinary action against the employee. 

Incident response: System logs 

Scenario: A company experiences a security breach, and the forensic team is tasked with identifying the source of the intrusion. By analyzing the system.log and appfirewall.log files on a compromised macOS server, they discover multiple failed login attempts followed by a successful remote access session. Further investigation into the logs reveals that the attacker installed a backdoor, which was used to maintain persistent access. The forensic team uses this information to contain the breach, remove the backdoor, and bolster the system’s defenses. 

Magnet Axiom and Axiom Cyber: Essential tools for macOS forensics 

When it comes to conducting thorough and efficient investigations on macOS systems, tools like Magnet Axiom and Magnet Axiom Cyber are invaluable. These advanced digital forensics tools streamline the process of uncovering, analyzing, and presenting key macOS forensics artifacts, making them essential for criminal investigations, insider threat analysis, and incident response. 

Magnet Axiom is designed to empower investigators with the ability to examine data from a wide variety of sources, including computer systems, mobile devices, and cloud services. For macOS forensics investigations, Axiom provides powerful capabilities to collect and analyze critical artifacts such as user home directories, system logs, browser histories, keychain data, and more. The platform’s intuitive interface and automated artifact extraction ensure that investigators can quickly locate and interpret the evidence necessary to build a strong case. 

One of the standout features of Magnet Axiom is its ability to create comprehensive timelines. By pulling data from different sources—whether it’s file system logs, application usage, or internet activity—Axiom enables investigators to reconstruct events with precision. This is particularly beneficial in mac forensics investigations where piecing together user activity across different artifacts, such as system logs and Safari browsing history, can provide a clearer picture of what transpired on the device. 

Magnet Axiom Cyber extends these capabilities to corporate environments, offering remote acquisition and analysis features that are crucial for modern-day investigations. In cases of insider threats or remote incident response, Axiom Cyber allows forensic teams to collect and analyze data from macOS systems across multiple locations without needing physical access to the devices. This ability to perform remote acquisition ensures that critical evidence is preserved quickly and securely, minimizing the risk of data tampering or loss. 

Axiom and Axiom Cyber’s ability to integrate cloud-based data into investigations is also crucial for modern Linux environments, where cloud services and remote access are common. With the rise of cloud storage and online services, it’s not uncommon for evidence to be scattered across multiple platforms. By seamlessly combining on-premises and cloud data, they provide a comprehensive view of the incident, ensuring that no piece of evidence is overlooked. 

Get the right toolkit for macOS forensics 

In summary, Magnet Axiom and Magnet Axiom Cyber provide investigators with a comprehensive toolkit for macOS forensics. These tools not only enhance the efficiency of the investigation process but also ensure that all potential sources of evidence are thoroughly explored. Whether you’re dealing with a criminal case, an insider threat, or a cybersecurity incident, Magnet Axiom and Magnet Axiom Cyber provide the capabilities necessary to uncover the truth and support the pursuit of justice.