Final Flashcards
Forensics
The use of science and technology to investigate and establish facts in criminal or civil courts of law.
Relevant evidence
- tendency to make a fact more or less probable then it would be without evidence. 2. the fact is of consequence in determining the action.
digital evidence
information of probative value stored or transmitted in digital form
digital media
physical objects where data is stored
computer use in crime
contraband, tool for the crime, incidental to the Crime
contraband
digital equipment etc was illegally obtained
tool of crime
hacking
incidental to the crime
digital media has evidence of the crime(phone contacts etc)
types of investigations
internal, civil, criminal
daubert standard
judge makes a call on if the scientific expert is basing their reason on proven scientific methodology. Daubert challenge is if you use anything thats not accepted by a majority of professionals
Locard’s principle of Transference
you can’t interact with an environment without leaving something behind
Inman-Rudin Paradigm
transfer, identification, individualization (narrowing evidence to certain classification), association (linking to a person or system), reconstruction (what happened), sixth principle (evidence must divide before transfer)
cross validation
any forensic artifact must be discoverable with multiple tools and techniques
6 As
Assessment (gathering information, chain of custody, determine scope, protect media), acquisition (make the copy of the data), authentication (verify copies), analysis (looking for the artifacts), articulation (drafting and submitting the report), archival (Storage of media, notes, and report).
What are hashes used for
- determining if data is unique. 2. determine if data is the same. 3. determine if any changes have been made to the data
Floppy disk life span
2 years
CD-RW life span
3 years or up to 50 with proper storage
USB drive life span
up to 10 if not heavily used
hard drive life span
up to 34 years
evidence
ANY INFORMATION OF PROBATIVE VALUE
Best Evidence
most complete copy of evidence that was obtained that is most closely linked to the original evidence
Computer components that hold evidence
hard drives, removable media, RAM (has to be collected through live analysis), motherboard BIOS, scanners, printers
Network devices that hold evidence
clients, servers, routers, gateways, firewalls, network printers, NAS (network attached storage)
magnetized media
holds a series of charges. Pro: very large storage capacity, data can be overwritten without being reset. Cons: slow access time, slow random read and write
Hard Drive Physical components
platters (magnetized surface containing charge), Read/Write heads (electromagnets used for reading or changing charges), Arm (moves read/write head towards the inside of the disk)
Hard Drive Logical Components
Tracks-rings that go completely around the center of the platter. Cylanders- tracks that line up on parallel platters
Hard Drive Sectors
Pie-Shaped wedge tracks (a sector is the smallest unit of data that can be read or written from magnetic storage media
Two Hard Drive Interfaces
IDE and SATA
Floppy disk forensics
treat like a single platter hard drive
magnetic media forensics
never truly wiped, data isn’t erased before overwritten
optical media forensics
cd-rom, blue ray disk, DVD-rom. (inherently read only), writing data must be done to the entire disk at once
RAID
Redundant array of independent disks - used to prevent hardware failure
RAID Levels
0 - block stripping (data distributed among multiple drives) one drive fails all fail. 1 - disk mirroring data written to two disks simultaneously. onE disk fails the other comes online. 2- disk mirroring with ECC (NOT USED). 3- Byte stripping with parity. 4- block stripping with parity drive.
Three RAID implementations
Internal Hardware (RAID controller card), external hardware (enclosure in a separate cabinet), software, cannot boot off a software RAID volume
How to acquire RAID data?
boot the suspect computer into a forensically sound environment and acquire raid volume. In encase: device view, select drives, edit disk config, specify RAID
SSDs
uses modified transistors for non-volatile storage, very fast data access, issues with recovering deleted data.
Assembly
low level language for microprocessors
order of memory speed
registers, caches, main memory, disk storage
4 kinds of memory
Internal (registers and CPU cache), main memory (RAM), on-line mass storage (Hard drive, ssd, usb), offline bulk storage (tape arrays)