Forensic Investigation Case Study

Title: Cat got your tongue?

Background

In the state of Western Australia it is illegal to access, own or distribute digital content relating to ‘cats’. Jane, the network administrator for the Daily Planet was reviewing network traffic logs when she noticed that an employee may have been accessing digital content relating to cats. The network administrator informed their line manager (Ash), and Ash notified the police. A junior police officer attended the company’s premises and assessed the network traffic logs, confirming that there is a high probability that digital content relating to cats had been accessed via a computer owned by an individual named Clark. Police obtained the necessary documents and seized the equipment relating to the allegation.

The suspect Clark was formally interviewed and denied accessing any content relating to cats. To date, Clark does not have a criminal record. Paul Ekman was coincidentally onsite during the interview, and was asked to examine the video of the interview. Paul made a statement suggesting that Clark’s micro facial expressions didn’t quite “add up”. Clark was interviewed again, but this time used the malware defence. Paul Ekman and the forensic investigators concluded that “something wasn’t quite right”, and they concluded that this would be a suitable challenge for you, the new recruit within the department.

You have been assigned the task of examining a “forensic image” of the suspect’s laptop which was seized with the appropriate warrants and imaged using forensically sound practices. At this point in time, there is insufficient evidence to make any generalisations or conclusions regarding the case. The network logs conclusively suggest that Clark’s computer was used to access the illegal content.

Unfortunately, the junior forensic investigator who obtained a “forensic image” of the computer only performed a logical acquisition. To make matters worse, the junior investigator accidently, securely wipe the laptop’s entire hard drive. Fortunately, the logical acquisition was undertaken in a forensically sound manner and can still be used within the investigation. The MD5 hash of the forensic image is “044288459e2fd193e446eec8de0acdd9”.

Task

Your task is to investigate the supplied forensic image using appropriate tools and forensic process and to develop and submit a written report on your findings. You may use any tools to undertake the investigation but you must justify all of your actions!

Report Structure

Additional Task Information

• Start early and plan ahead, you may need to spend some time experimenting with various tools. If a tool or method fails to result in a successful outcome you should still document this action in your running sheet. Each tool has its own strengths and limitations.
• Each report will be unique and presented in its own way.
• Scrutinise the marking key, and ask any questions you may have EARLY in the semester!
• Look for clues/hints in the investigation. Strategically placed clues/hints have been created in this fictitious case study to help you along the way.
• It is not expected that you find every piece of evidence and nor do you have to. Furthermore, should there password protected or encrypted content – you do not necessarily have to break/decrypt it to successfully progress with the investigation.
• Remember to ensure the integrity of the image being investigated. You should continually demonstrate that you have maintained integrity throughout your investigation.
• Consider what you are trying to find and what you need to negate. The background information of this document, provides carefully developed clues.

Marking Key