Question 540
Cleanup is not considered complete. The case record describes: A phishing email links to a lookalike login site that asks for a one-time code immediately after the password. Which remediation task is necessary rather than merely suppressing the visible symptom?
- Revoke active identity sessions and block the phishing destination
- Correlate the phishing URL, sign-in sequence and unexpected session/token activity
- Reset credentials and review account grants and mailbox changes
- Use phishing-resistant authentication and conditional access protections
- Review affected account logins and revoke compromised sessions
Explanation
Correct Answer
C:The attacker may have established persistence after authenticating; the recovery decision is tied to whether an adversary-in-the-middle login capture occurred, not merely to reduced alert volume.
Incorrect Answers
A:Token revocation helps terminate access that password reset alone might not stop; the requirement concerns whether an adversary-in-the-middle login capture occurred, so temporary protection does not complete correction.
B:Captured credentials and session artifacts may permit access beyond password knowledge; the goal is trusted restoration for whether an adversary-in-the-middle login capture occurred. Verification is not the corrective step.
D:Strong origin-bound factors reduce session-theft opportunities; the case needs trusted restoration addressing whether an adversary-in-the-middle login capture occurred; future hardening is not current-state recovery.
E:Mobile-origin authentication may still expose corporate identities; the relevant condition for that step is whether the QR destination is a phishing site, which is not shown for whether an adversary-in-the-middle login capture occurred.
Question 541
Before granting routine access again, the team reviews this case: An API service fails under a small number of computationally expensive authenticated search requests. What must the response owner validate as part of safe recovery?
- Apply endpoint-specific rate limits and cost caps to abusive clients
- Use per-client quotas, query budgets and abuse analytics
- Validate caching and resolver service health before restoring external access
- Optimize expensive queries and confirm capacity after controls apply
Explanation
Correct Answer
D:A sustainable fix addresses resource amplification; it is the corrective action needed for whether application-layer resource exhaustion is responsible after the immediate hazard is controlled.
Incorrect Answers
A:Application-aware throttling targets expensive requests; when judging whether application-layer resource exhaustion is responsible, temporary protection does not complete correction; this is instead initial containment or preservation.
B:Business-aware controls limit layer-seven denial of service; for whether application-layer resource exhaustion is responsible, future hardening is not current-state recovery; trusted restoration remains necessary.
C:Correct recovery confirms normal name resolution for legitimate users; this serves whether resolver resource exhaustion is the outage cause, whereas the requested result is trusted restoration involving whether application-layer resource exhaustion is responsible.
Question 542
The team has retained the initial evidence and is assessing recovery from: A visitor plugs a consumer access point into a conference-room Ethernet jack, exposing an internal VLAN. What restoration task closes the identified integrity or control gap?
- Use network access control and restrict unused switch ports
- Remove confirmed unauthorized equipment and review any associated clients
- Disable the affected switch port and secure the rogue hardware under procedure
- Restore approved VLAN configuration and investigate connections made through the AP
Explanation
Correct Answer
D:Recovery includes the exposure window, not just unplugging equipment; the change should be tested before unrestricted operations resume for the event involving whether a rogue AP bridges a protected wired segment.
Incorrect Answers
A:Port admission policies reduce rogue infrastructure; the goal is trusted restoration for whether a rogue AP bridges a protected wired segment. Future hardening is not current-state recovery.
B:A rogue device may have captured traffic or credentials; the relevant condition for that step is whether the radio is authorized infrastructure, which is not shown for whether a rogue AP bridges a protected wired segment.
C:Port-level containment removes the unintended bridge; the case needs trusted restoration addressing whether a rogue AP bridges a protected wired segment; temporary protection does not complete correction.
Question 543
While full remediation remains pending, the commander receives this incident report: DNS monitoring reports many TXT lookups containing unusually long random strings from a single host. Which first protective measure directly limits the situation without assuming cleanup is finished?
- Inspect query lengths, label entropy, resolver logs and initiating process
- Temporarily restrict the unapproved destination after validating business ownership
- Limit the suspect host's DNS egress to approved resolvers and isolate as needed
- Find the initiating process and remove the tunnel mechanism and persistence
Explanation
Correct Answer
C:Routing control interrupts covert outbound channels; the scope of this restriction follows whether DNS tunneling may carry encoded data rather than indiscriminately changing unrelated assets.
Incorrect Answers
A:Encoded payloads often manifest as repetitive atypical labels and record usage; the case needs initial containment or preservation addressing whether DNS tunneling may carry encoded data; investigation alone does not control current conditions.
B:Selective containment avoids terminating legitimate protected backup traffic; it is meant to address whether unusual egress is approved backup or exfiltration, not initial containment or preservation for whether DNS tunneling may carry encoded data.
D:Blocking one domain does not fix a compromised host; the requirement concerns whether DNS tunneling may carry encoded data, so corrective follow-through follows initial protection.
Question 544
The recovery owner is reviewing the underlying failure in this report: Packet captures are available but no sensor covers the segment between two data-center application tiers. What action most directly repairs the affected access, evidence or system state?
- Validate alternate management access and normal control flows before restoration
- Deploy appropriate east-west sensors and verify collection accuracy
- Enable scoped capture at an authorized aggregation or switch mirror point
- Test network visibility during red-team and incident exercises
Explanation
Correct Answer
B:Persistent coverage should include high-value internal paths; the resulting state needs verification against the original concern: whether network monitoring sees suspected east-west movement.
Incorrect Answers
A:Recovery must verify the safety system remains functional; the relevant condition for that step is whether segmentation plans protect critical operational dependencies, which is not shown for whether network monitoring sees suspected east-west movement.
C:Targeted visibility supports analysis without changing endpoint state; for whether network monitoring sees suspected east-west movement, temporary protection does not complete correction; trusted restoration remains necessary.
D:Coverage validation reveals gaps missed by perimeter-only monitoring; the requirement concerns whether network monitoring sees suspected east-west movement, so future hardening is not current-state recovery.
Question 545
During lessons learned, the security owner reviews this completed incident: A warehouse barcode scanner connects to an open guest SSID rather than its protected operational WLAN. Which repeatable safeguard best prevents this failure mode in the future?
- Deploy locked-down device WLAN profiles and certificate-based authentication
- Reprovision the scanner onto the approved secured SSID and rotate affected credentials
- Review scanner WLAN profile, association records and transmitted application protocol
- Enforce validated enterprise WLAN certificates and managed network profiles
Explanation
Correct Answer
A:Managed association policies prevent accidental insecure roaming; it closes a repeatable gap revealed by whether client misassociation caused insecure traffic without removing useful monitoring.
Incorrect Answers
B:Restoring intended association must address secrets possibly exposed; when judging whether client misassociation caused insecure traffic, case recovery is not future-risk control; this is instead trusted restoration.
C:An open wireless association changes confidentiality and access assumptions; for whether client misassociation caused insecure traffic, an investigation is not recurrence prevention; recurrence prevention remains necessary.
D:Client authentication helps prevent evil-twin connections; the other incident centers on whether an evil twin access point is impersonating the SSID, not this recurrence prevention question about whether client misassociation caused insecure traffic.
Question 546
The recurrence-prevention decision is based on this report: A compromised identity establishes a reverse SSH tunnel from a database host to an external server. What measure strengthens readiness against the observed event?
- Remove unauthorized keys and startup entries and rotate exposed credentials
- Correlate SSH process arguments with firewall flows and local listening ports
- Manage SSH keys centrally and alert on unexpected remote port forwarding
- Use unique local admin credentials and restrict RDP to managed jump hosts
Explanation
Correct Answer
C:Controls reduce covert tunneling through legitimate tools; the ongoing control is targeted at whether outbound encrypted traffic enables inbound control, rather than a one-time emergency fix.
Incorrect Answers
A:Eradication closes both access and persistence mechanisms; the requirement concerns whether outbound encrypted traffic enables inbound control, so case recovery is not future-risk control.
B:A reverse tunnel can expose internal services through an outbound connection; the goal is recurrence prevention for whether outbound encrypted traffic enables inbound control. An investigation is not recurrence prevention.
D:Tiered remote management reduces lateral exposure; the relevant condition for that step is whether local credential reuse enabled RDP spread, which is not shown for whether outbound encrypted traffic enables inbound control.
Question 547
The first task is to corroborate an alert. The case notes state: A security analyst sees multiple TCP resets but mistakes them for proof of an active denial-of-service attack. What should the investigator examine to distinguish a substantiated finding from an assumption?
- Correlate SYN and response patterns with successful handshakes and service logs
- Inspect packet rates, response codes and service availability together
- Set baselines for connection rates and service health indicators
- Apply mitigation only after validating impact and the offending traffic source
Explanation
Correct Answer
B:Resets can arise from policy, application behavior or deliberate interference; this evidence is scoped to whether resets reflect malicious flooding or normal session behavior, not a generic system-health reading.
Incorrect Answers
A:Incomplete connection attempts suggest reconnaissance but do not prove application compromise; this serves whether the traffic represents probing rather than established access, whereas the requested result is evidence validation involving whether resets reflect malicious flooding or normal session behavior.
C:Context improves network anomaly classification; prevention is not incident verification in the decision about whether resets reflect malicious flooding or normal session behavior.
D:An unsupported emergency filter could worsen availability; the case needs evidence validation addressing whether resets reflect malicious flooding or normal session behavior; immediate protection does not substantiate findings.
Question 548
Service owners need a bounded short-term safeguard after observing: A website experiences a flood of SYN packets that fills connection-state tables at the network edge. What immediate action addresses the active exposure and leaves evidence available?
- Enable appropriate upstream SYN mitigation and rate-limiting capacity
- Inspect SYN versus completed-handshake rates and firewall state utilization
- Confirm normal handshakes and clean policy state after mitigation
- Engage the ISP or scrubbing provider for upstream diversion and filtering
Explanation
Correct Answer
A:Protection should reduce bogus half-open connections before table exhaustion; the immediate response addresses whether state exhaustion is driving the outage while the team preserves relevant case records.
Incorrect Answers
B:SYN imbalance together with exhausted connection state supports this flood type; for whether state exhaustion is driving the outage, investigation alone does not control current conditions; initial containment or preservation remains necessary.
C:Recovery needs service-health validation, not just lower packet counts; the requirement concerns whether state exhaustion is driving the outage, so corrective follow-through follows initial protection.
D:Mitigation before the bottleneck restores usable bandwidth; the activity targets where traffic must be filtered to restore availability; initial containment or preservation here concerns whether state exhaustion is driving the outage.
Question 549
The incident owner requests a defensible factual determination after hearing: A corporate Wi-Fi client associates to an unknown access point through a weak pre-shared key reused at a partner site. What fact-checking activity tests the observed failure most directly?
- Prefer per-user or per-device enterprise authentication over shared PSKs
- Review access point authentication events and key distribution history
- Compare BSSID, radio location, authentication certificate and approved AP inventory
- Rotate the exposed key and remove the unapproved device from coverage
Explanation
Correct Answer
B:A shared passphrase does not distinguish authorized users individually; it makes the determination of whether PSK exposure allows unauthorized association defensible and reviewable by the incident owner.
Incorrect Answers
A:Unique credentials enable revocation and accountability; prevention is not incident verification in the decision about whether PSK exposure allows unauthorized association.
C:A familiar SSID can be broadcast by a rogue access point; the activity targets whether an evil twin access point is impersonating the SSID; evidence validation here concerns whether PSK exposure allows unauthorized association.
D:Containment blocks continued access using the reused secret; for whether PSK exposure allows unauthorized association, immediate protection does not substantiate findings; evidence validation remains necessary.
Question 550
A triage analyst needs to test a report involving these details: A router configuration backup exists only on the router that may have been modified by an intruder. Which evidence collection or correlation is most relevant to this claim?
- Compare topology documentation and active routing with the referenced firewall path
- Maintain immutable off-device network configuration backups
- Restrict administrative changes and preserve current configuration evidence
- Restore a verified approved configuration and rotate device administration secrets
- Compare current running configuration with an independently retained approved backup
Explanation
Correct Answer
E:A local copy could share the compromised state or have been overwritten; the review should retain source and timing information relevant to whether trusted baseline configurations are available.
Incorrect Answers
A:An obsolete enforcement point cannot stop traffic that bypasses it; the other incident centers on whether emergency network enforcement points are current, not this evidence validation question about whether trusted baseline configurations are available.
B:Independent baselines support dependable incident recovery; prevention is not incident verification in the decision about whether trusted baseline configurations are available.
C:Containment should prevent additional tampering before correction; the case needs evidence validation addressing whether trusted baseline configurations are available; immediate protection does not substantiate findings.
D:A known-good baseline addresses configuration and credential compromise; when judging whether trusted baseline configurations are available, recovery is not factual verification; this is instead trusted restoration.