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Free SY0-801 practice test: 30 questions with answers
30 original questions for CompTIA Security+ (V8), drawn from every topic area. Answer each one to see whether you got it right and why. No sign-up.
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All 30 SY0-801 questions with answers
The same questions as the test above, grouped by exam topic. Open any question to see the answer and explanation.
Security Operations (6 questions)
Question 1
A SIEM receives authentication failures from many hosts within minutes of each other, followed by a success from an unusual location. Which SIEM capability links these events into one alert?
- ACorrelation rules that combine related events across sources into a single incident
- BFull-disk encryption on the SIEM server, protecting stored logs with AES-256
- CA DHCP lease log archive kept on a file share, listing client MAC addresses
- DA printer status dashboard showing toner levels, paper trays, and job queue
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Correct answer: ACorrelation rules join related events by time, source, and pattern, which reveals a probable password attack. Disk encryption, DHCP logs, and printer dashboards do not connect events across sources.
Question 2
Which two actions most directly harden endpoints against malware that arrives through removable media? (Choose two.)
- ARestrict or block removable storage through device control policy
- BDisable the endpoint protection agent to improve performance
- CEnable automatic execution of files from USB drives
- DKeep operating system and application patches current
- EGrant every user local administrator rights to simplify work
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Correct answer: A, DDevice control limits what can connect and scan or block dangerous media, and current patches reduce exploitable flaws. Disabling protection, auto-running media, and granting admin rights each increase the chance of compromise.
Question 3
During an incident, responders isolate affected hosts, remove the malware, and restore systems from clean backups. Which phase of incident response does this describe?
- AInitial identification
- BEradication and recovery
- CLessons learned notes
- DPreparation and team training
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Correct answer: BRemoving the cause and restoring systems belongs to eradication and recovery. Preparation happens before incidents, identification confirms the event, and lessons learned follows the response.
Question 4
A vulnerability scan of servers reports many missing patches on hosts where the scanner has no administrative credentials. What should the team do to get accurate results?
- AScan the public company website hosted on the DMZ web tier and treat it as the inventory of exposed hosts
- BIgnore the results because the scanner is not logged in, and the missing patches are assumed to be noise
- CDisable the scanner for those servers and exclude them from the scan schedule until the next audit cycle
- DRun authenticated scans using a dedicated scanning account with appropriate read permissions
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Correct answer: DAuthenticated scans can inspect installed packages and patch levels, producing far more accurate findings. Ignoring results or disabling scans leaves gaps, and scanning only a website misses the servers.
Question 5
A company must prevent employees from emailing customer credit card numbers outside the organization. Which control enforces this most directly?
- AA longer email retention period for archived messages on the server
- BBlocking outbound internet traffic from workstations at the perimeter firewall
- CData loss prevention rules that detect and block sensitive data in outbound email
- DA reminder in the employee handbook that card data must not be emailed
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Correct answer: CDLP inspects content and blocks or quarantines sensitive data leaving the organization. A handbook reminder is advisory, retention periods do not prevent sending, and blocking all internet traffic is disproportionate.
Question 6
An endpoint detection and response tool identifies a process that is injecting code into another process. Which capability of the tool best supports investigation of this behavior?
- ABehavioral telemetry showing process trees and memory activity for the affected host
- BA list of printers currently installed on the host and their driver versions
- CA count of monthly help desk tickets opened for password resets during the last quarter
- DA report of the number of desktop wallpapers and screensaver images installed across the managed fleet
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Correct answer: AEDR telemetry captures process relationships and behaviors that reveal code injection and its context. Wallpapers, printers, and ticket counts do not describe the process activity.
Threats, Vulnerabilities, and Attacks (6 questions)
Question 7
An attacker sends a convincing email to a finance manager, referencing a real vendor invoice and the manager's name, asking for an urgent wire transfer. Which attack type is this?
- ASQL injection
- BSpear phishing
- CRootkit installation
- DDenial of service
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Correct answer: BSpear phishing targets a specific person using tailored details, here a real invoice and the manager's name. Denial of service, SQL injection, and rootkits do not rely on targeted deception of a person.
Question 8
An attacker tries one common password against thousands of accounts in a directory, moving slowly to avoid lockouts. Which attack is this?
- APassword spraying
- BBrute-force attack against one account
- CSession hijacking
- DKeylogging
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Correct answer: APassword spraying tries a few passwords across many accounts to avoid lockout thresholds. Brute force targets one account with many guesses, while keylogging captures typed input and hijacking steals an active session.
Question 9
An attacker positions themselves between a client and a server, relaying messages while reading or altering them. Which attack is this?
- ACross-site scripting vector
- BMan-in-the-middle attack
- CTyposquatting domains
- DZero-day exploit kit
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Correct answer: BA man-in-the-middle attack intercepts and possibly modifies traffic between two parties. Cross-site scripting injects script into web pages, a zero-day is an unpatched vulnerability, and typosquatting registers look-alike names.
Question 10
Ransomware has encrypted files on a file server, and a note demands payment. Which control best reduces the impact of this attack?
- ARemoving antivirus from the server to avoid conflicts
- BOffline or immutable backups tested for restoration
- CStoring backups on the same server
- DA longer password for the file server administrator only
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Correct answer: BOffline or immutable backups that have been tested allow recovery without paying the ransom. Backups on the same server can be encrypted too, and password length or removing antivirus does not limit the damage.
Question 11
Which two signs most strongly suggest a social engineering attempt against an employee? (Choose two.)
- AA team meeting invitation appears on the calendar with a normal agenda
- BA caller claims urgent authority and pressures the employee to skip normal verification
- CA colleague asks for help with a document on a shared drive during business hours
- DThe request asks for a password reset code to be read out over the phone
- EA system update notification appears on a managed device after its scheduled window
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Correct answer: B, DPressure to bypass verification and requests for one-time codes are classic social engineering indicators. Routine work requests, scheduled updates, and normal invitations are expected activity.
Question 12
A malicious update is inserted into a trusted software vendor's build process, and customers install it through the normal update channel. Which attack category does this represent?
- ABrute-force attack
- BSupply chain attack
- CDenial-of-service attack
- DCredential stuffing
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Correct answer: BCompromising the vendor's build or distribution process to reach many customers is a supply chain attack. Brute force, denial of service, and credential stuffing target access or availability differently.
Security Architecture (6 questions)
Question 13
A company wants to stop trusting users and devices simply because they are inside the corporate network. Which model does this describe?
- AAir gap
- BDefense in depth only
- CSecurity through obscurity
- DZero trust
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Correct answer: DZero trust verifies every request based on identity, device health, and context regardless of network location. An air gap isolates a network, while defense in depth layers controls without changing the trust assumption, and obscurity is not a security model.
Question 14
A company wants to limit the damage if a single workstation is compromised, so that it cannot reach the payroll servers directly. Which design achieves this?
- ADisabling host firewalls on each workstation to simplify routing between the user VLAN
- BPlacing workstations and servers together on one flat network for easier management
- CSharing one local administrator password across the workstation and payroll subnets
- DNetwork segmentation that places payroll servers in a separate zone with restricted access rules
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Correct answer: DSegmentation with restricted rules limits lateral movement from a compromised device. A flat network and shared credentials make lateral movement easy, and disabling firewalls removes a control.
Question 15
In a cloud deployment, the provider secures the physical data center and hypervisor, while the customer configures its own identities and data access. Which concept describes this division?
- AMandatory access control
- BAir-gapped architecture
- CShared responsibility model
- DLeast privilege policy
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Correct answer: CThe shared responsibility model divides security duties between provider and customer based on the service. Least privilege governs access rights, mandatory access control enforces labels, and air gaps are a network isolation method.
Question 16
A company wants users to prove who they are with something they know and something they have. Which authentication approach matches this?
- AMultifactor authentication
- BSingle-factor authentication with a long password
- CAuthentication based only on IP address
- DAnonymous access with a shared token
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Correct answer: ACombining a knowledge factor with a possession factor is multifactor authentication. A single long password is one factor, IP-based checks are not identity proof, and shared tokens and anonymity offer no individual proof.
Question 17
Which two benefits do honeypots and deception systems provide? (Choose two.)
- AObserving attacker techniques without exposing production data
- BReplacing the need to patch production systems
- CCollecting attacker tools in an isolated environment
- DIncreasing the attack surface of the production network
- EAutomatically blocking all traffic from the internet
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Correct answer: A, CDecoy systems let defenders watch attacker methods and capture tools in isolation, without risking production data. They do not replace patching, enlarge the production attack surface, or block internet traffic.
Question 18
Which two components are part of a public key infrastructure? (Choose two.)
- AA printer queue that manages print jobs
- BA firewall rule set for inbound web traffic
- CA spreadsheet of user passwords
- DCertificate authority that signs and issues certificates
- ERegistration authority that verifies identities before certificate requests
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Correct answer: D, EThe certificate authority signs certificates, and the registration authority verifies the requester's identity before issuance. Printer queues, firewall rules, and password spreadsheets are not PKI components.
General Security Concepts (6 questions)
Question 19
A hospital ensures that a patient record cannot be altered without detection by using a cryptographic digest that is compared on each access. Which security goal is this?
- AIntegrity
- BConfidentiality
- CAvailability
- DNon-repudiation only
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Correct answer: ADigests detect unauthorized modification, which protects integrity. Availability concerns access when needed, and confidentiality concerns disclosure, while non-repudiation is about proving origin rather than detecting change.
Question 20
Two parties need to exchange a large volume of encrypted messages quickly. Which type of cryptography is typically used for the bulk data after a secure key exchange?
- ASteganography
- BAsymmetric encryption only
- CSymmetric encryption
- DHashing only
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Correct answer: CSymmetric encryption is fast and suited to bulk data, and asymmetric cryptography is typically used to exchange or authenticate the shared key. Hashing does not encrypt, and steganography hides data rather than encrypting it.
Question 21
A system stores passwords as salted hashes. Why is the salt added before hashing?
- ATo make the password reversible for support staff who must recover lost credentials
- BTo shorten the stored hash so each account row in the database uses less disk space
- CTo allow the password to be sent in plaintext during login so the server can compare it directly
- DTo defeat precomputed lookup tables by making identical passwords produce different hashes
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Correct answer: DA unique salt per password makes precomputed rainbow-table attacks impractical and identical passwords produce different hashes. Salting does not make hashes reversible, shorten them, or permit plaintext transmission.
Question 22
A user logs in and the system checks which resources the user may access, then records what the user did. Which set of concepts is this?
- ARouting, switching, and packet forwarding
- BEncryption, hashing, digital signing, and key exchange
- CAuthentication, authorization, and accounting
- DScanning, patching, and asset inventory
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Correct answer: CAAA covers verifying identity, deciding permitted actions, and logging activity. The other sets describe cryptographic operations, vulnerability management, and network forwarding.
Question 23
Which two statements about cryptographic hashing are correct? (Choose two.)
- ATwo different inputs should produce different digests in a secure hash function
- BHashing is used to provide confidentiality for stored messages without any key
- CA hash of a file changes when the file is modified even slightly
- DA hash function produces a fixed-length digest from input of any length
- EA hash can be reversed to recover the original input when the key is known
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Correct answer: A, DHash functions produce fixed-length outputs and are designed to make collisions infeasible, and any change to the input changes the digest. Hashes are one-way and do not provide confidentiality on their own, and the other statements contradict these properties.
Question 24
A web client checks whether a server certificate has been revoked before trusting it. Which mechanism provides this check?
- AFile Transfer Protocol for moving TLS certificate bundles to web servers
- BCertificate revocation list or Online Certificate Status Protocol
- CSimple Mail Transfer Protocol for relaying transactional email from web servers
- DDynamic Host Configuration Protocol for allocating IP addresses to hosts
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Correct answer: BCRLs and OCSP are the revocation checking mechanisms that tell clients whether a certificate is still valid. DHCP, SMTP, and FTP do not check certificate status.
Security Program Management and Oversight (6 questions)
Question 25
A risk register lists a vulnerability in a payment system with a likelihood of 4 out of 5 and an impact of 5 out of 5. What is the best next step under a risk management process?
- ADelete it from the risk register to clean up the list and reduce the number of items
- BIgnore it because a likelihood and impact score is merely a subjective estimate of risk
- CAccept the risk informally and leave the decision undocumented while the payment
- DPrioritize it for treatment, assign an owner, and set a remediation deadline
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Correct answer: DA high likelihood and impact score calls for prompt treatment with an accountable owner and deadline. Ignoring, undocumented acceptance, or deleting the entry removes oversight of a serious risk.
Question 26
A security manager needs written direction that states what the organization must do for passwords, while a separate document explains the steps staff follow to reset them. Which pair of artifacts is this?
- AA policy and a procedure
- BA baseline and a vendor contract
- CA checklist and a diagram
- DA standard and a log file
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Correct answer: AA policy states mandatory requirements, and a procedure gives step-by-step instructions to implement them. Baselines, contracts, logs, checklists, and diagrams serve other purposes.
Question 27
A company must manage the risk that a cloud vendor handles its customer data and could suffer a breach. Which activity is most appropriate?
- AAssuming the vendor is secure because it is large and has a compliance certificate
- BSharing the vendor's customer data with subcontractors without review
- CThird-party risk assessment with contractual security requirements and periodic review
- DNot documenting the vendor relationship or the data it stores in the asset inventory
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Correct answer: CThird-party assessments and contract clauses set security expectations, and periodic review confirms they are met. Assuming security, skipping documentation, and sharing data without review each leave the risk unmanaged.
Question 28
A company wants to identify which business functions must be restored first after a disaster and the financial impact of their downtime. Which activity should it perform?
- AA social phishing simulation
- BA business impact analysis
- CA penetration test of web apps
- DA vulnerability scan on servers
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Correct answer: BA business impact analysis identifies critical functions, dependencies, and the cost of downtime, which sets recovery priorities. Scans, penetration tests, and phishing simulations test technical controls rather than business priorities.
Question 29
A company processes personal data of residents of the European Union. Which regulation must its privacy program address?
- AThe Sarbanes-Oxley Act
- BThe Payment Card Industry Data Security Standard only
- CThe Federal Aviation Regulations
- DThe General Data Protection Regulation
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Correct answer: DGDPR governs the processing of personal data about people in the EU. SOX applies to financial reporting in US public companies, PCI DSS covers card data, and aviation regulations are unrelated.
Question 30
Which two elements are typically included in a security awareness program? (Choose two.)
- APeriodic simulated phishing exercises with feedback
- BPublishing employee passwords to show what not to do
- CRemoving all reporting channels to avoid noise
- DRegular training on phishing recognition and reporting
- EInstructions on how to share passwords with a trusted colleague
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Correct answer: A, DPhishing training and simulations build recognition and reporting habits. Sharing passwords, publishing them, and removing reporting channels all weaken security and are never part of an awareness program.