Beginner’s Guide to Computer Forensics

Introduction
Computer forensics is the practice of collecting, analysing and reporting on digital information in a way that is legally admissible. It can be used in the detection and prevention of crime and in any dispute where evidence is stored digitally. Computer forensics has comparable examination stages to other forensic disciplines and faces similar issues.

About this guide
This guide discusses computer forensics from a neutral perspective. It is not linked to particular legislation or intended to promote a particular company or product and is not written in bias of either law enforcement or commercial computer forensics. It is aimed at a non-technical audience and provides a high-level view of computer forensics. This guide uses the term “computer”, but the concepts apply to any device capable of storing digital information. Where methodologies have been mentioned they are provided as examples only and do not constitute recommendations or advice. Copying and publishing the whole or part of this article is licensed solely under the terms of the Creative Commons – Attribution Non-Commercial 3.0 license

Uses of computer forensics
There are few areas of crime or dispute where computer forensics cannot be applied. Law enforcement agencies have been among the earliest and heaviest users of computer forensics and consequently have often been at the forefront of developments in the field. Computers may constitute a ‘scene of a crime’, for example with hacking [ 1] or denial of service attacks [2] or they may hold evidence in the form of emails, internet history, documents or other files relevant to crimes such as murder, kidnap, fraud and drug trafficking. It is not just the content of emails, documents and other files which may be of interest to investigators but also the ‘meta-data’ [3] associated with those files. A computer forensic examination may reveal when a document first appeared on a computer, when it was last edited, when it was last saved or printed and which user carried out these actions.

More recently, commercial organisations have used computer forensics to their benefit in a variety of cases such as;

Intellectual Property theft
Industrial espionage
Employment disputes
Fraud investigations
Forgeries
Matrimonial issues
Bankruptcy investigations
Inappropriate email and internet use in the work place
Regulatory compliance

Guidelines
For evidence to be admissible it must be reliable and not prejudicial, meaning that at all stages of this process admissibility should be at the forefront of a computer forensic examiner’s mind. One set of guidelines which has been widely accepted to assist in this is the Association of Chief Police Officers Good Practice Guide for Computer Based Electronic Evidence or ACPO Guide for short. Although the ACPO Guide is aimed at United Kingdom law enforcement its main principles are applicable to all computer forensics in whatever legislature. The four main principles from this guide have been reproduced below (with references to law enforcement removed):

No action should change data held on a computer or storage media which may be subsequently relied upon in court.

In circumstances where a person finds it necessary to access original data held on a computer or storage media, that person must be competent to do so and be able to give evidence explaining the relevance and the implications of their actions.

An audit trail or other record of all processes applied to computer-based electronic evidence should be created and preserved. An independent third-party should be able to examine those processes and achieve the same result.

The person in charge of the investigation has overall responsibility for ensuring that the law and these principles are adhered to.

In summary, no changes should be made to the original, however if access/changes are necessary the examiner must know what they are doing and to record their actions.

Live acquisition
Principle 2 above may raise the question: In what situation would changes to a suspect’s computer by a computer forensic examiner be necessary? Traditionally, the computer forensic examiner would make a copy (or acquire) information from a device which is turned off. A write-blocker[4] would be used to make an exact bit for bit copy [5] of the original storage medium. The examiner would work then from this copy, leaving the original demonstrably unchanged.

However, sometimes it is not possible or desirable to switch a computer off. It may not be possible to switch a computer off if doing so would result in considerable financial or other loss for the owner. It may not be desirable to switch a computer off if doing so would mean that potentially valuable evidence may be lost. In both these circumstances the computer forensic examiner would need to carry out a ‘live acquisition’ which would involve running a small program on the suspect computer in order to copy (or acquire) the data to the examiner’s hard drive.

By running such a program and attaching a destination drive to the suspect computer, the examiner will make changes and/or additions to the state of the computer which were not present before his actions. Such actions would remain admissible as long as the examiner recorded their actions, was aware of their impact and was able to explain their actions.

Stages of an examination
For the purposes of this article the computer forensic examination process has been divided into six stages. Although they are presented in their usual chronological order, it is necessary during an examination to be flexible. For example, during the analysis stage the examiner may find a new lead which would warrant further computers being examined and would mean a return to the evaluation stage.

Readiness
Forensic readiness is an important and occasionally overlooked stage in the examination process. In commercial computer forensics it can include educating clients about system preparedness; for example, forensic examinations will provide stronger evidence if a server or computer’s built-in auditing and logging systems are all switched on. For examiners there are many areas where prior organisation can help, including training, regular testing and verification of software and equipment, familiarity with legislation, dealing with unexpected issues (e.g., what to do if child pornography is present during a commercial job) and ensuring that your on-site acquisition kit is complete and in working order.

Evaluation
The evaluation stage includes the receiving of clear instructions, risk analysis and allocation of roles and resources. Risk analysis for law enforcement may include an assessment on the likelihood of physical threat on entering a suspect’s property and how best to deal with it. Commercial organisations also need to be aware of health and safety issues, while their evaluation would also cover reputational and financial risks on accepting a particular project.

Collection
The main part of the collection stage, acquisition, has been introduced above. If acquisition is to be carried out on-site rather than in a computer forensic laboratory then this stage would include identifying, securing and documenting the scene. Interviews or meetings with personnel who may hold information which could be relevant to the examination (which could include the end users of the computer, and the manager and person responsible for providing computer services) would usually be carried out at this stage. The ‘bagging and tagging’ audit trail would start here by sealing any materials in unique tamper-evident bags. Consideration also needs to be given to securely and safely transporting the material to the examiner’s laboratory.

Analysis
Analysis depends on the specifics of each job. The examiner usually provides feedback to the client during analysis and from this dialogue the analysis may take a different path or be narrowed to specific areas. Analysis must be accurate, thorough, impartial, recorded, repeatable and completed within the time-scales available and resources allocated. There are myriad tools available for computer forensics analysis. It is our opinion that the examiner should use any tool they feel comfortable with as long as they can justify their choice. The main requirements of a computer forensic tool is that it does what it is meant to do and the only way for examiners to be sure of this is for them to regularly test and calibrate the tools they use before analysis takes place. Dual-tool verification can confirm result integrity during analysis (if with tool ‘A’ the examiner finds artefact ‘X’ at location ‘Y’, then tool ‘B’ should replicate these results.)

Presentation
This stage usually involves the examiner producing a structured report on their findings, addressing the points in the initial instructions along with any subsequent instructions. It would also cover any other information which the examiner deems relevant to the investigation. The report must be written with the end reader in mind; in many cases the reader of the report will be non-technical, so the terminology should acknowledge this. The examiner should also be prepared to participate in meetings or telephone conferences to discuss and elaborate on the report.

Review
Along with the readiness stage, the review stage is often overlooked or disregarded. This may be due to the perceived costs of doing work that is not billable, or the need ‘to get on with the next job’. However, a review stage incorporated into each examination can help save money and raise the level of quality by making future examinations more efficient and time effective. A review of an examination can be simple, quick and can begin during any of the above stages. It may include a basic ‘what went wrong and how can this be improved’ and a ‘what went well and how can it be incorporated into future examinations’. Feedback from the instructing party should also be sought. Any lessons learnt from this stage should be applied to the next examination and fed into the readiness stage.

Issues facing computer forensics
The issues facing computer forensics examiners can be broken down into three broad categories: technical, legal and administrative.

Encryption – Encrypted files or hard drives can be impossible for investigators to view without the correct key or password. Examiners should consider that the key or password may be stored elsewhere on the computer or on another computer which the suspect has had access to. It could also reside in the volatile memory of a computer (known as RAM [6] which is usually lost on computer shut-down; another reason to consider using live acquisition techniques as outlined above.

Increasing storage space – Storage media holds ever greater amounts of data which for the examiner means that their analysis computers need to have sufficient processing power and available storage to efficiently deal with searching and analysing enormous amounts of data.

New technologies – Computing is an ever-changing area, with new hardware, software and operating systems being constantly produced. No single computer forensic examiner can be an expert on all areas, though they may frequently be expected to analyse something which they haven’t dealt with before. In order to deal with this situation, the examiner should be prepared and able to test and experiment with the behaviour of new technologies. Networking and sharing knowledge with other computer forensic examiners is also very useful in this respect as it’s likely someone else may have already encountered the same issue.

Anti-forensics – Anti-forensics is the practice of attempting to thwart computer forensic analysis. This may include encryption, the over-writing of data to make it unrecoverable, the modification of files’ meta-data and file obfuscation (disguising files). As with encryption above, the evidence that such methods have been used may be stored elsewhere on the computer or on another computer which the suspect has had access to. In our experience, it is very rare to see anti-forensics tools used correctly and frequently enough to totally obscure either their presence or the presence of the evidence they were used to hide.

Legal issues
Legal arguments may confuse or distract from a computer examiner’s findings. An example here would be the ‘Trojan Defence’. A Trojan is a piece of computer code disguised as something benign but which has a hidden and malicious purpose. Trojans have many uses, and include key-logging [7], uploading and downloading of files and installation of viruses. A lawyer may be able to argue that actions on a computer were not carried out by a user but were automated by a Trojan without the user’s knowledge; such a Trojan Defence has been successfully used even when no trace of a Trojan or other malicious code was found on the suspect’s computer. In such cases, a competent opposing lawyer, supplied with evidence from a competent computer forensic analyst, should be able to dismiss such an argument.

Accepted standards – There are a plethora of standards and guidelines in computer forensics, few of which appear to be universally accepted. This is due to a number of reasons including standard-setting bodies being tied to particular legislations, standards being aimed either at law enforcement or commercial forensics but not at both, the authors of such standards not being accepted by their peers, or high joining fees dissuading practitioners from participating.

Fitness to practice – In many jurisdictions there is no qualifying body to check the competence and integrity of computer forensics professionals. In such cases anyone may present themselves as a computer forensic expert, which may result in computer forensic examinations of questionable quality and a negative view of the profession as a whole.

Picture Framing Online: A Perfect Gift For Him

Deciding a perfect gift for men is quite a hectic job. Even though there are lots of gifting options these days, there will always be confusion on how should you pick the item! Would he appreciate it or. Most women end up buying t-shirts, wallets or shoes. However, if you are looking for personalized and unique gift ideas, then you can try out picture framing online services. Get one of the custom picture frames and collage the bitter sweet memories of your relationship. Your partner will definitely like this and will appreciate your effort.

Additionally, you can take a picture of him, especially when he is not aware and get it framed. You can take many of such photos, line them together and frame. If that is not enough you can gather his childhood pictures and jam it with the recent ones with beautiful messages. This would make him emotional for sure. These picture framing online are all-purpose gifts, from birthday, anniversary to just a usual gift. The best thing is that these items are available online, so even if you are feeling reluctant to visit a physical store, you can always sit at the comfort of your home and place an order.

The frames vary in shapes, sizes and quality. You get to choose from a plethora of options, ranging from wooden to metal. You will find square and rectangular photo frames. There could be variations in colour too, including golden, silver, cream and black. Based on the occasion and purpose you can choose the one. As for the size, these ecommerce sites have measurement options. You need to select from the one.
The online framing service providers offer beautifully carved frames. They boast amazing designs and are of high quality. They would be excellent gifts for sure.

If not his phoThe online framing service providers offer beautifully carved frames. They boast amazing designs and are of high quality. They would be excellent gifts for sure. to, you can think of any theme photo and get it framed with wonderful quotes. Also, if your partner loves nature photography you can take one and get it framed for him. However, when you are choosing a frame make sure you are buying from a good store. There will be many who claim to be the best, but that is hardly the truth.

Besides, there are some who fail to meet the delivery deadline. You will of course not want your gift to be delivered lately, particularly when the occasion is gone. In order to ensure that the gift reaches to the concerned person on time you can live chat with the people or make a special request. The custom picture frames can be gift wrapped as well if you want. However, you might have to pay a little extra for that. Else you can be lucky to get free gift packaging..

The Best Online Gaming Buys

If you are an online gamer, the term MMORPG is a term you are familiar with. Or even you are not, then you probably have been playing it all along with no clue of it name. Your MMORPG experience can your new source of income if you have any eso gold in account that you wish to sell. Your financial woes end here at S and F where we conclude your deals and hook you up with the bestbuyer in exchange for your eso gold. For adrenaline junkies in gaming, there is the adrenaline bot to increase your online gaming experience. The map control is one of the most amazing features that has got gamers hooked to it.
The bot is able to see all the floors and many places and you can draw your map to mark the zone that are laden with obstacles such as trees or rocks.You may as well decide to sell or buy an account according to your preference as we are here to meet your expectations and so much more. You will have to secure the account with your password once you have purchased it and received the necessary login information.

Many gaming stores have sprouted from nowhere all claiming to offer such services such as the adrenaline bot but we here to redefine the concept as many of them do not know what they are dealing with. We are doing so by providing quality transactions in terms of efficiency and transparency. Many gamers have come to S and F to sell or buyeso gold after having unsuccessfully tried with dubious sites that may be out to dupe them. The adrenaline bot gives you best settings for the game conditions out of game interface panel. This bot is exceptional in its family and will offer you unsurpassed gaming experience so that you can get the best out of the Elder Scrolls online. If the game is becoming somewhat boring, don’t hesitate to sell your account all the eso gold init.

Sellers and Friendshas been the best gaming store that online gamers can now call home as we make sure to stock all our servers with eso gold so as to meet the demand. Some cash on the side is sure way to reward yourself after all the hours spent online playing your favorite game. The prices we offer are insane and we accept payments from PayPal, Skrill as well as Bank Transfer. Give us a visit today at Sellers and Friends you will realize that selling eso gold has never been easier. We help you finalize the deal between you and the buyer for your eso gold. We also have on display a list of items that have been ordered by gamers so that sellers can view them easily. S & F can also find the desired game item for you. Entrust us with your virtual items such gold and coins as well and accounts. We will find the best buyers for them and settle a deal for you.