Computer forensics or digital forensics is a term in computer science to acquire authorized proof found in digital media or computers storage. With digital forensic investigation, the investigator can find what occurred to the digital media equivalent to emails, hard disk, logs, computer system, manitoba and the network itself. In lots of case, forensic investigation can produce how the crime might happened and the way we will defend ourselves towards it subsequent time.
Some the reason why we have to conduct a forensic investigation: 1. To assemble evidences in order that it can be used in court to resolve legal cases. 2. To analyze our network strength, and to fill the security gap with patches and fixes. 3. To recover deleted files or any recordsdata within the event of hardware or software failure
In computer forensics, an important issues that must be remembered when conducting the investigation are:
1. The unique proof must not be altered in anyhow, and to do conduct the method, forensic investigator should make a bit-stream image. Bit-stream image is a bit by bit copy of the unique storage medium and actual copy of the unique media. The distinction between a bit-stream image and regular copy of the original storage is bit-stream image is the slack area in the storage. You’ll not discover any slack house data on a copy media.
2. All forensic processes must observe the authorized legal guidelines in corresponding nation the place the crimes happened. Each country has different law suit in IT field. Some take IT guidelines very critically, for example: United Kingdom, Australia.
3. All forensic processes can solely be carried out after the investigator has the search warrant.
Forensic investigators would usually trying 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 urged to create a Digital Forensic Crew or First Responder Team, in order that the corporate might nonetheless preserve the evidence until the forensic investigator come to the crime scene.
First Response rules are: 1. Under no circumstances ought to anyone, excluding Forensic Analyst, to make any makes an attempt to recuperate data from any computer system or device that holds digital information. 2. Any attempt to retrieve the information by particular person stated in number 1, should be averted as it may compromise the integrity of the proof, through which grew to become inadmissible in authorized court.
Based on that rules, it has already explained the vital roles of having a First Responder Team in a company. The unqualified individual can only secure the perimeter in order that nobody can touch the crime scene till Forensic Analyst has come (This can be executed by taking picture of the crime scene. They’ll also make notes about the scene and who were current at that time.
Steps must be taken when a digital crimes happenred in an expert means: 1. Secure the crime scene until the forensic analyst arrive.
2. Forensic Analyst should request for the search warrant from local authorities or company’s management.
3. Forensic Analyst make take an image of the crime scene in case of if there isn’t a any photographs has been taken.
4. If the computer continues to be powered on, don’t turned off the computer. As a substitute, used a forensic tools similar to Helix to get some data that may solely be found when the computer continues to be powered on, similar to knowledge on RAM, and registries. Such instruments has it’s particular perform as to not write something back to the system so the integrity stay intake.
5. Once all live evidence is collected, Forensic Analyst cant turned off the computer and take harddisk back to forensic lab.
6. All the evidences have to be documented, wherein chain of custody is used. Chain of Custody maintain information on the evidence, akin to: who has the evidence for the final time.
7. Securing the evidence have to be accompanied by authorized officer equivalent to police as a formality.
8. Back in the lab, Forensic Analyst take the evidence to create bit-stream image, as unique proof must not be used. Usually, Forensic Analyst will create 2-5 bit-stream image in case 1 image is corrupted. In fact Chain of Custody nonetheless used in this state of affairs to keep records of the evidence.
9. Hash of the unique proof and bit-stream image is created. This acts as a proof that unique proof and the bit-stream image is the precise copy. So any alteration on the bit image will end in totally different hash, which makes the evidences found change into inadmissible in court.
10. Forensic Analyst starts to search out evidence in the bit-stream image by rigorously wanting on the corresponding location is determined by what kind of crime has happened. For example: Short-term Internet Recordsdata, Slack House, Deleted File, Steganography files.