What's the best way to handle evidence tampering in incident response forensics?

As a career professional focused on audit, risk, and compliance activities, the lifecycle of evidence management is paramount to the very purpose of why we collect evidence in the first place. We must consider our practices, procedures, technology, and vigilance towards the necessity of immutability of evidence. It is always difficult when you have a determined adversary, but even the Village Idiot has his day too. Success starts with a plan!

Evidence tampering occurs when someone purposely changes or destroys evidence that's important for a criminal investigation or trial. For instance, if someone steals something and then hides the stolen item to avoid getting caught, that's evidence tampering. This kind of behavior makes it harder for authorities to find out the truth about what happened. From a legal assistant's point of view, tampering with evidence messes up the fairness of trials and the whole process of figuring out what really occurred. Legal assistants are like detectives who make sure everything's fair and square in court, and when evidence gets tampered with, it makes their job harder to uncover the truth.

Malicious tampering aims to conceal actions or mislead investigations, while unintentional tampering results from procedural errors or inadequate tools. To mitigate these risks, establish stringent protocols for evidence handling, storage, and analysis. Train responders thoroughly and use validated tools to ensure evidence remains intact and credible. Vigilant adherence to these practices safeguards the authenticity of evidence and supports the integrity of investigations and legal processes.

Having a written policy and procedural component in place is the first step towards a robust chain-of-custody and evidence management program. Words however do not stop physical actions. Enforcing your rules with some type of technology is essential. When I created the evidence management system for Continuum GRC, I decided to utilize Blockchain. One of the core properties of blockchain is immutability, meaning that once data is recorded on the blockchain, it cannot be altered or tampered with. Each piece of evidence can be time-stamped and cryptographically linked to a previous block, forming an unbreakable chain of information. This ensures that evidence remains unchanged and reliable, providing a tamper-proof record of events.

Detecting evidence tampering requires vigilance and a thorough understanding of the evidence being analyzed. Here are some key methods for identifying it: - Examining Documentation for Discrepancies - Analyzing Digital Evidence for Anomalies - Verifying Hash Values - Checking Digital Signatures - Performing Physical Inspections - Seeking Expert Reviews - Utilizing Forensic Analysis - Recognizing Patterns - Performing Network Analysis - Documenting Findings thoroughly

Hashing is crucial, as it generates a unique value for files or disk images, enabling comparison between original and copied evidence to spot alterations. Timestamps, metadata, and logs further reveal inconsistencies or anomalies that may indicate tampering. By scrutinizing these elements, you can uncover discrepancies in the timeline or trace the sources of tampering. This multi-faceted approach not only helps identify potential evidence tampering but also ensures the integrity and reliability of your investigative processes.

Blockchain has several features that make it highly useful for the prevention of evidence tampering. Here are some additional ways in which Blockchain enhances the integrity and security of evidence. Similar to how the Internet works, Blockchain operates as a distributed ledger across multiple nodes making it highly resistant to manipulation. Blockchain networks utilize consensus algorithms to achieve agreement among nodes meaning an attacker would need to have control over most of the network, making such attacks computationally infeasible and expensive. Blockchain employs cryptographic algorithms to encrypt and authenticate data. Finally, Blockchain's transparency enables an immutable audit trail. The proverbial Canary in the Coalmine!

Implement rigorous chain of custody procedures to document every instance of evidence handling, ensuring a clear and unbroken history. Use write protection tools, like hardware or software write blockers, to prevent accidental or intentional alterations during acquisition and analysis. Encrypt data to safeguard it from unauthorized access or tampering, both during storage and transmission. These practices collectively ensure that evidence remains pristine, secure, and reliable throughout the investigative and judicial processes.

Collectively, these features make Blockchain a valuable tool for preventing evidence tampering, bolstering trust, and ensuring the integrity of information in a wide range of applications, including legal, forensic, and supply chain management systems. The Security Trifecta methodology employing governance, technology, and vigilance remains the stalwart approach to both physical and digital security. There are many approaches to thwarting evidence tampering aside from Blockchain which are also effective. I founded Lazarus Alliance to help companies identify and eliminate business risks measured against industry standards and Continuum GRC to provide tools that make them more effective. Like I remind my team, work smarter, not harder!

One of the key stages in the digital forensics process is the structured collection of forensic data, which involves capturing and preserving electronic evidence in a meticulous manner to ensure its integrity and admissibility in legal proceedings. Maintaining the chain of custody throughout the investigation is crucial to establishing the authenticity and reliability of the evidence, preventing tampering or alteration that could compromise its validity. Write protection devices, such as hardware or software write blockers, can prevent any accidental or intentional changes to evidence during acquisition.

There is no policy, procedure, or technology that is perfectly infallible. You can spend massive amounts of resources on software and hardware only to have it all come crashing down because of the wetware (humans) who have access or gain access to your business ecosystem.

Consider WFH and BYOD. Big risk there. Depends on what tools you have installed on your personal device, but hopefully any sensitive data would be on a company device with MDM and FDE and a scanning agent.