Computer forensics or digital forensics is a term in computer science to obtain legal evidence present in digital media or computers storage. With digital forensic investigation, the investigator can find what happened to the digital media corresponding to emails, hard disk, logs, computer system, and the network itself. In many case, forensic investigation can produce how the crime may occurred and how we are able to protect ourselves against it subsequent time.
Some the explanation why we need to conduct a forensic investigation: 1. To gather evidences in order that it can be utilized in court to unravel authorized cases. 2. To investigate our network energy, and to fill the security hole with patches and fixes. 3. To recuperate deleted files or any files in the occasion of hardware or software program failure
In computer dfi forensics, a very powerful issues that should be remembered when conducting the investigation are:
1. The original evidence must not be altered in anyways, and to do conduct the process, forensic investigator should make a bit-stream image. Bit-stream image is a little by little copy of the original storage medium and precise copy of the unique media. The difference between a bit-stream image and regular copy of the original storage is bit-stream image is the slack area within the storage. You’ll not discover any slack space information on a copy media.
2. All forensic processes should follow the authorized legal guidelines in corresponding nation the place the crimes happened. Every nation has completely different law suit in IT field. Some take IT rules very significantly, for example: United Kingdom, Australia.
3. All forensic processes can only be conducted after the investigator has the search warrant.
Forensic investigators would normally trying on the timeline of how the crimes happened in timely manner. With that, we are able to produce the crime scene about how, when, what and why crimes could happened. In a big firm, it’s recommended to create a Digital Forensic Crew or First Responder Crew, in order that the corporate might still protect the proof till the forensic investigator come to the crime scene.
First Response rules are: 1. On no account ought to anybody, except Forensic Analyst, to make any attempts to get better info from any computer system or machine that holds digital information. 2. Any try to retrieve the data by particular person mentioned in number 1, must be prevented as it might compromise the integrity of the evidence, in which turned inadmissible in legal court.
Primarily based on that guidelines, it has already defined the vital roles of getting a First Responder Crew in a company. The unqualified particular person can only safe the perimeter so that nobody can touch the crime scene until Forensic Analyst has come (This may be executed by taking photo of the crime scene. They can additionally make notes about the scene and who were present at that time.
Steps have to be taken when a digital crimes occurred in an expert approach: 1. Secure the crime scene till the forensic analyst arrive.
2. Forensic Analyst must request for the search warrant from native authorities or firm’s management.
3. Forensic Analyst make take a picture of the crime scene in case of if there is no such thing as a any pictures has been taken.
4. If the computer is still powered on, do not turned off the computer. As a substitute, used a forensic instruments reminiscent of Helix to get some data that can solely be discovered when the computer is still powered on, equivalent to information on RAM, and registries. Such tools has it is special perform as to not write anything back to the system so the integrity keep intake.
5. As soon as all live evidence 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 preserve information on the evidence, similar to: who has the proof for the final time.
7. Securing the proof have to be accompanied by legal officer comparable to police as a formality.
8. Back in the lab, Forensic Analyst take the proof to create bit-stream image, as authentic proof must not be used. Normally, Forensic Analyst will create 2-5 bit-stream image in case 1 image is corrupted. Of course Chain of Custody still used in this scenario to keep information of the evidence.
9. Hash of the original proof and bit-stream image is created. This acts as a proof that unique proof and the bit-stream image is the exact copy. So any alteration on the bit image will lead to totally different hash, which makes the evidences found turn into inadmissible in court.
10. Forensic Analyst begins to search out proof in the bit-stream image by rigorously trying at the corresponding location depends on what sort of crime has happened. For example: Temporary Internet Files, Slack Area, Deleted File, Steganography files.