Computer forensics or digital forensics is a term in computer science to obtain authorized evidence present in digital media or computers storage. With digital forensic investigation, the investigator can discover what happened to the digital media corresponding to emails, hard disk, logs, computer system, and the network itself. In lots of case, forensic investigation can produce how the crime could happened and unfaithful how we can protect ourselves in opposition to it subsequent time.
Some reasons why we have to conduct a forensic investigation: 1. To collect evidences so that it may be utilized in court to unravel authorized cases. 2. To investigate our network strength, and to fill the safety gap with patches and fixes. 3. To get well deleted recordsdata or any recordsdata in the event of hardware or software program failure
In computer forensics, crucial issues that need to be remembered when conducting the investigation are:
1. The unique evidence must not be altered in anyways, and to do conduct the process, forensic investigator must make a bit-stream image. Bit-stream image is a bit by bit copy of the unique storage medium and actual copy of the original media. The distinction between a bit-stream image and regular copy of the unique storage is bit-stream image is the slack space within the storage. You’ll not find any slack house info on a copy media.
2. All forensic processes must observe the authorized laws in corresponding country the place the crimes happened. Each country has different regulation suit in IT field. Some take IT guidelines very critically, for instance: United Kingdom, Australia.
3. All forensic processes can solely be carried out after the investigator has the search warrant.
Forensic investigators would normally wanting at the timeline of how the crimes occurred in timely manner. With that, we are able to produce the crime scene about how, when, what and why crimes might happened. In a big firm, it’s steered to create a Digital Forensic Workforce or First Responder Crew, in order that the company might still preserve the proof until the forensic investigator come to the crime scene.
First Response guidelines are: 1. Certainly not ought to anyone, apart from Forensic Analyst, to make any attempts to recover information from any computer system or gadget that holds electronic information. 2. Any attempt to retrieve the info by particular person said in number 1, should be averted because it could compromise the integrity of the evidence, in which turned inadmissible in legal court.
Based on that rules, it has already defined the important roles of having a First Responder Staff in a company. The unqualified particular person can only secure the perimeter in order that nobody can contact the crime scene until Forensic Analyst has come (This may be done by taking picture of the crime scene. They will also make notes in regards to the scene and who were current at that time.
Steps must be taken when a digital crimes occurred in knowledgeable method: 1. Secure the crime scene till the forensic analyst arrive.
2. Forensic Analyst should request for the search warrant from local authorities or firm’s management.
3. Forensic Analyst make take an image of the crime scene in case of if there isn’t any any photos has been taken.
4. If the computer remains to be powered on, don’t turned off the computer. As a substitute, used a forensic tools reminiscent of Helix to get some data that can only be found when the computer continues to be powered on, similar to information on RAM, and registries. Such instruments has it is special operate as to not write anything back to the system so the integrity stay intake.
5. As soon as all live proof is collected, Forensic Analyst cant turned off the computer and take harddisk back to forensic lab.
6. All of the evidences must be documented, wherein chain of custody is used. Chain of Custody keep data on the proof, comparable to: who has the proof for the final time.
7. Securing the evidence should be accompanied by legal officer such as police as a formality.
8. Back in the lab, Forensic Analyst take the evidence to create bit-stream image, as authentic proof should not be used. Normally, Forensic Analyst will create 2-5 bit-stream image in case 1 image is corrupted. After all Chain of Custody nonetheless used in this situation to keep data of the evidence.
9. Hash of the unique proof and bit-stream image is created. This acts as a proof that authentic evidence and the bit-stream image is the exact copy. So any alteration on the bit image will result in different hash, which makes the evidences discovered grow to be inadmissible in court.
10. Forensic Analyst begins to seek out proof within the bit-stream image by carefully trying on the corresponding location depends upon what sort of crime has happened. For example: Temporary Internet Files, Slack House, Deleted File, Steganography files.