New Technology Reviews!.: Field

IntroductionComputer forensic examiners are responsible for technical acuity, knowledge of the law, and objectivity in the course of investigations. Success is principled upon verifiable and repeatable reported results that represent direct evidence of suspected wrong-doing or potential exoneration. This article establishes a series of best practices for the computer forensics practitioner, representing the best evidence for defensible solutions in the field. Best practices themselves are intended to capture those processes that have repeatedly shown to be successful in their use. This is not a cookbook. Best practices are meant to be reviewed and applied based on the specific needs of the organization, the case and the case setting.Job KnowledgeAn examiner can only be so informed when they walk into a field setting. In many cases, the client or the client's representative will provide some information about how many systems are in question, their specifications, and their current state. And just as often, they are critically wrong. This is especially true when it comes to hard drive sizes, cracking laptop computers, password hacking and device interfaces. A seizure that brings the equipment back to the lab should always be the first line of defense, providing maximum flexibility. If you must perform onsite, create a comprehensive working list of information to be collected before you hit the field. The list should be comprised of small steps with a checkbox for each step. The examiner should be completely informed of their next step and not have to "think on their feet."OverestimateOverestimate effort by at least a factor of two the amount of time you will require to complete the job. This includes accessing the device, initiating the forensic acquisition with the proper write-blocking strategy, filling out the appropriate paperwork and chain of custody documentation, copying the acquired files to another device and restoring the hardware to its initial state. Keep in mind that you may require shop manuals to direct you in taking apart small devices to access the drive, creating more difficulty in accomplishing the acquisition and hardware restoration. Live by Murphy's Law. Something will always challenge you and take more time than anticipated -- even if you have done it many times.Inventory Equipment Most examiners have enough of a variety of equipment that they can perform forensically sound acquisitions in several ways. Decide ahead of time how you would like to ideally carry out your site acquisition. All of us will see equipment go bad or some other incompatibility become a show-stopper at the most critical time. Consider carrying two write blockers and an extra mass storage drive, wiped and ready. Between jobs, make sure to verify your equipment with a hashing exercise. Double-Check and inventory all of your kit using a checklist before taking off.Flexible AcquisitionInstead of trying to make "best guesses" about the exact size of the client hard drive, use mass storage devices and if space is an issue, an acquisition format that will compress your data. After collecting the data, copy the data to another location. Many examiners limit themselves to traditional acquisitions where the machine is cracked, the drive removed, placed behind a write-blocker and acquired. There are also other methods for acquisition made available by the Linux operating system. Linux, booted from a CD drive, allows the examiner to make a raw copy without compromising the hard drive. Be familiar enough with the process to understand how to collect hash values and other logs. Live Acquisition is also discussed in this document. Leave the imaged drive with the attorney or the client and take the copy back to your lab for analysis.Pull the PlugHeated discussion occurs about what one should do when they encounter a running machine. Two clear choices exist; pulling the plug or performing a clean shutdown (assuming you can log in). Most examiners pull the plug, and this is the best way to avoid allowing any sort of malevolent process from running that may delete and wipe data or some other similar pitfall. It also allows the examiner access to create a snapshot of the swap files and other system information as it was last running. It should be noted that pulling the plug can also damage some of the files running on the system, making them unavailable to examination or user access. Businesses sometimes prefer a clean shutdown and should be given the choice after being explained the impact. It is critical to document how the machine was brought down because it will be absolutely essential knowledge for analysis.Live AcquisitionsAnother option is to perform a live acquisition. Some define "live" as a running machine as it is found, or for this purpose, the machine itself will be running during the acquisition through some means. One method is to boot into a customized Linux environment that includes enough support to grab an image of the hard drive (often among other forensic capabilities), but the kernel is modified to never touch the host computer. Special versions also exist that allow the examiner to leverage the Window's autorun feature to perform Incident Response. These require an advanced knowledge of both Linux and experience with computer forensics. This kind of acquisition is ideal when for time or complexity reasons, disassembling the machine is not a reasonable option.The FundamentalsAn amazingly brazen oversight that examiner's often make is neglecting to boot the device once the hard disk is out of it. Checking the BIOS is absolutely critical to the ability to perform a fully-validated analysis. The time and date reported in the BIOS must be reported, especially when time zones are an issue. A rich variety of other information is available depending on what manufacturer wrote the BIOS software. Remember that drive manufacturers may also hide certain areas of the disk (Hardware Protected Areas) and your acquisition tool must be able to make a full bitstream copy that takes that into account. Another key for the examiner to understand is how the hashing mechanism works: Some hash algorithms may be preferable to others not necessarily for their technological soundness, but for how they may be perceived in a courtroom situation.Store SecurelyAcquired images should be stored in a protected, non-static environment. Examiners should have access to a locked safe in a locked office. Drives should be stored in antistatic bags and protected by the use of non-static packing materials or the original shipping material. Each drive should be tagged with the client name, attorney's office and evidence number. Some examiners copy drive labels on the copy machine, if they have access to one during the acquisition and this should be stored with the case paperwork. At the end of the day, each drive should link up with a chain of custody document, a job, and an evidence number.Establish a PolicyMany clients and attorneys will push for an immediate acquisition of the computer and then sit on the evidence for months. Make clear with the attorney how long you are willing to maintain the evidence at your lab and charge a storage fee for critical or largescale jobs. You may be storing critical evidence to a crime or civil action and while from a marketing perspective it may seem like a good idea to keep a copy of the drive, it may be better from the perspective of the case to return all copies to the attorney or client with the appropriate chain of custody documentation.ConclusionComputer examiners have many choices about how they will carry out an onsite acquisition. At the same time, the onsite acquisition is the most volatile environment for the examiner. Tools may fail, time constraints can be severe, observers may add pressure, and suspects may be present. Examiners need to take seriously the maintenance of their tools and development of ongoing knowledge to learn the best techniques for every situation. Utilizing the best practices herein, the examiner should be prepared for almost any situation they may face and have the ability to set reasonable goals and expectations for the effort in question.	 	 		 			 				 					 						Carol L. Stimmel is a Certified Computer Examiner (CCE), co-author of The Manager Pool, and former Vice-President, Consulting of Gartner. She has worked in technology for over 15 years and has been involved in engineering, security, knowledge management, and the establishment of successful entrepreneurial ventures.CITSF provides certified consulting services to the attorney marketplace in the area of computer forensics and e-discovery.Visit CITSF on the web at <a href="http://www.citsf.com" target="_new">http://www.citsf.com</a> She may be reached at 303-819-2068 or carol.stimmel@gmail.com.

Best Practices for Computer Forensics in the Field

Introduction Computer forensic examiners are responsible for technical acuity, knowledge of the law, and objectivity in the course of in...

In the global village called the internet, not everyone plays nice. You always hear of the word "hack". It is mostly used in relation to invading of computers. Most of these are not entirely true but computer network systems do get hacked. If and when it does happen, it usually involves something sinister.Even employees of companies do engage in snooping or to use our favorite word, hacking. The birth of the internet has led to more of this. Anyone can be anything online. This is why fraud, phishing, and identity theft happen.The computer has become an important part of everyday life. Sending letters have been entirely changed by emails. Communications have been dominated by instant and text messaging. Portable storage devices that were an exclusive preserve of Information Technology professionals are now used by the general public.I think you are already getting the idea of why computer forensics are needed. In the event that hacking does occur, the computer forensic will do the following:1.	Like any other investigation, the computer forensic must handle the area as a crime scene. He or she will take digital photographs and secure documentary evidence. This will include printouts, notes and disks in the scene.If you are the one who hired the computer forensic expert, you should leave everything to them. The computer system should be left as is whether it is turned on or off.If the computer was left on, the analyst will gather all the information that he or she can from the running applications. The computer will then be shutdown in a way that the data will not be lost. Doing a standard shutdown or pulling the plug is not an option. Both of these methods may cause the loss or damage of the data in the computer system.2. The forensic investigator must then document the configuration of the system as you would document a crime scene. This should include the order of hard drives, modem, LAN, storage subsystems, cable connections, and wireless networking hardware. The analyst may make a diagram to go along with the digital photographs. They will also take portable storage devices within the area that may contain substantial evidence.3. The computer forensic expert must take all the evidence to the lab. This is because the analyst should not examine the evidence in the same hardware. People who engage in cyber crimes are also aware that important data can be retrieved to convict them. Countermeasures, viruses and booby traps may be installed in the system to damage electronic evidence.Analysts take the hard drive in their lab instead to make an exact duplicate of its contents. This process is called Imaging. Analysts have their own tools to make sure that the data is copied completely and accurately.The duplicate will then be verified by an algorithm. The data is then examined and analyzed. The analyst makes a report of his or her findings and the process that was taken during the investigation starting from the acquisition of the data. This evidence will be presented in court if prosecution is necessary.The computer forensic plays many roles and duties in the criminal justice field. It is hard to cover all of them in this short article. I encourage you to do more reading if you are interested in this field. You can do this by visiting websites that cover the profession in more detail.Note: You are free to reprint or republish this article. The only condition is that the links should be clickable.	 	 		 			 				 					 						Copywrite Kenneth Echie. Kenneth writes for <a href="http://www.criminaljustice-schools-degrees.com" target="_new">Criminal Justice Degrees</a>. Get free scholarship report and learn about <a href="http://www.criminaljustice-schools-degrees.com/computer-forensics.html" target="_new">Computer Forensics</a> by visiting.

The Roles and Duties of the Computer Forensic in the Criminal Justice Field

In the global village called the internet, not everyone plays nice. You always hear of the word "hack". It is mostly used in re...