Incident Response and Forensics

Order is what these questions test. The phases run in one sequence, evidence is collected most volatile first, and getting either backwards is the wrong answer even when every individual step is right.

The six phases, in order

PhaseWhat happensCommon mistake
1. PreparationPlans, tooling, training, contactsTreating this as not part of the response
2. Detection and analysisConfirm it is real, scope itActing before scoping
3. ContainmentStop the spread, short and long termWiping before evidence is captured
4. EradicationRemove the cause, not the symptomReimaging without finding the entry point
5. RecoveryRestore and monitorRestoring from a backup taken after compromise
6. Lessons learnedWritten up, feeds preparationSkipping it once service is back

Order of volatility

OrderSourceWhy here
1CPU registers and cacheGone in nanoseconds
2RAM, running processes, network connectionsGone at power off
3Temporary files and swapOverwritten during normal use
4DiskSurvives reboot
5Remote logging and monitoring dataHeld elsewhere, but rotates
6Physical configuration and topologyStable
7Archival media and backupsMost stable

Evidence handling

TermWhat it means
Chain of custodyUnbroken record of who held evidence and when
Legal holdDuty to preserve data once litigation is anticipated
Write blockerReads a drive without altering it
Forensic imageBit-for-bit copy, work from this rather than the original
Hashing the imageProves the copy has not changed since acquisition
e-discoveryLocating and producing electronic evidence
ProvenanceWhere the data came from and how it got there
Data acquisition orderFollow order of volatility, document as you go

Exercise types

ExerciseWhat it involves
TabletopDiscussion around a scenario, no systems touched
WalkthroughStep through the plan, roles confirmed
SimulationA realistic event is staged and responded to
Parallel testRecovery systems brought up alongside production
Full interruptionProduction is actually failed over. Highest risk

Now test yourself

Memorizing a table is a start. Practice questions are what make it stick, and every answer carries the full explanation.