Cyber Security Interview Questions in Bangalore

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Office apps rarely start PowerShell, so this usually means a malicious macro or document exploit. Decode the Base64 command to see what it does, check the process tree and any network connections for downloads, and find the source email. Isolate the host through EDR, block the sender and URLs, search for the same email in other mailboxes and hunt for the same command line elsewhere.

Tell me about a time you learned a difficult technical topic quickly.

Cryptography and PKIEasy

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Situation: in my final year project I needed TLS mutual authentication for an IoT prototype within two weeks. Task: understand PKI enough to build it. Action: I read the TLS 1.3 overview, set up a small CA with OpenSSL, issued device certificates and tested failures deliberately. Result: the demo worked, and I documented the steps so classmates could reuse them, which helped our team score well.

How do you create a forensic disk image and verify it?

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Use a write blocker or a forensic tool, image the whole disk, and hash both source and image. sudo dc3dd if=/dev/sdb of=/evidence/case12.img hash=sha256 log=/evidence/case12.log sha256sum /evidence/case12.img Record the hashes, time, examiner and device details in the chain of custody form. Analyse a working copy, never the original.

You find a web shell on a public web server. What steps do you take?

Incident Response and ForensicsHard

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Do not just delete it. Capture the file, web logs and a memory image if possible, then identify when it was created and which request uploaded it. Search logs for commands executed through it and lateral movement from the server. Contain by isolating the server or blocking the path at the WAF, then patch the vulnerable application, rebuild from a clean image and rotate any credentials stored on it.

During a major breach, an engineer asks why legal and communications must join the war room. How do you explain?

Incident Response and ForensicsHard

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Legal advises on regulatory notification, such as CERT-In within six hours and the Data Protection Board and affected people under the DPDP Act, contractual duties to clients, evidence handling and privilege. Communications manage messaging to customers, staff, media and investors so statements are accurate and consistent. Technical teams should involve them early, because poor communication can cause more damage than the incident itself.

A developer has hardcoded database passwords in a public code repository. What do you do?

Security FundamentalsMedium

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Treat the secret as compromised immediately, even if the commit is removed, because public repos are scraped within minutes. Rotate the password and any related keys, check database logs for unknown logins since the commit time, and remove the secret from git history. Then fix the root cause by moving secrets to a vault or cloud secret manager and adding secret scanning to pre-commit hooks and the CI pipeline.

How would you verify the integrity of a downloaded installer on Windows and Linux?

Security FundamentalsEasy

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Compare the file's hash with the value published by the vendor over a trusted channel, or verify its digital signature. On Windows, use PowerShell and check the Authenticode signature. On Linux, use sha256sum and gpg for signed checksum files. Get-FileHash .\setup.exe -Algorithm SHA256 Get-AuthenticodeSignature .\setup.exe sha256sum tool.tar.gz gpg --verify SHA256SUMS.asc SHA256SUMS

How would you use Sysmon to improve endpoint visibility on Windows?

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Sysmon is a free Microsoft Sysinternals tool that logs detailed endpoint events to the Windows event log. Useful events are ID 1 process creation with hashes and command line, ID 3 network connection, ID 11 file creation, ID 13 registry changes and ID 22 DNS queries. With a tuned configuration, it gives rich telemetry for SIEM detections when a full EDR is not available or as an extra source.

How do you create a private key and CSR with OpenSSL?

Cryptography and PKIMedium

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Generate a key, then a certificate signing request to send to a CA. openssl ecparam -genkey -name prime256v1 -out server.key openssl req -new -key server.key -out server.csr \ -subj "/CN=portal.example.in" \ -addext "subjectAltName=DNS:portal.example.in" openssl req -in server.csr -noout -text Keep server.key private with restricted file permissions.

Your company website is under an application layer DDoS attack. What actions do you take?

Network SecurityHard

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Confirm it is an attack and not a traffic spike by checking request patterns, user agents and source spread. Enable or tighten the CDN or WAF bot protection and rate limits on targeted URLs, add challenge pages for suspicious clients, and cache heavy pages. Inform the ISP or DDoS provider and management. After the attack, review logs, tune rules and update the runbook.

What are the data residency rules relevant to cloud in India?

Cloud SecurityHard

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The DPDP Act 2023 allows cross-border transfer of personal data except to countries the government restricts, though sector rules can be stricter. RBI requires payment system data to be stored only in India. CERT-In requires ICT logs to be kept in India for 180 days. SEBI and IRDAI have their own requirements for regulated entities. Cloud architects choose Indian regions such as Mumbai or Hyderabad for compliance.

What is RBAC and ABAC?

Identity and Access ManagementMedium

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Role-Based Access Control grants permissions to roles such as Finance Analyst, and users get roles; it is simple to manage and audit. Attribute-Based Access Control decides using attributes of the user, resource and context, such as department, data classification, location and time. ABAC is more flexible but harder to reason about. Many organisations use RBAC as the base and add attribute conditions for sensitive cases.

How would you build a basic home SOC lab?

SOC Operations and SIEMEasy

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Use a laptop with virtualisation, run a Windows VM with Sysmon, a Linux server and a free SIEM such as Elastic or Splunk Free, or Wazuh as an open source option. Forward logs, then simulate attacks safely with Atomic Red Team tests on your own VMs. Write detections for each test, document them on GitHub and explain them in interviews.

How do you design an access review for a critical application?

Identity and Access ManagementMedium

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Define scope, such as all users with write or admin rights. Pull entitlements and last-login data from the app, and route each item to the user's manager and the app owner. Give clear choices of keep or revoke with a deadline, and revoke automatically if not reviewed. Capture evidence for auditors, and review exceptions with security. Run it quarterly for privileged access.

How do you inspect a certificate and check its chain?

Cryptography and PKIEasy

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Use OpenSSL to view the fields and verify the chain against the CA bundle. openssl x509 -in cert.pem -noout -subject -issuer -dates -ext subjectAltName openssl verify -CAfile chain.pem cert.pem openssl s_client -connect portal.example.in:443 -showcerts Check the SAN matches the hostname, the dates are valid, and the server sends intermediate certificates.

A TLS certificate expired on the main customer portal and caused an outage. How do you prevent this in future?

Cryptography and PKIMedium

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First renew and deploy the certificate to restore service. For prevention, build a certificate inventory from scanning and CT logs, automate issuance and renewal with ACME where possible, and set alerts at 30, 14 and 7 days before expiry to a team mailbox, not an individual. Assign an owner per certificate and add expiry checks to monitoring dashboards, since shorter lifetimes are coming.

A user on the office LAN reports repeated certificate warnings and you suspect ARP spoofing. What is happening and how do you stop it?

Network SecurityMedium

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ARP has no authentication, so an attacker on the same LAN can send fake ARP replies linking their MAC address to the gateway's IP. Victims then send traffic through the attacker, enabling man-in-the-middle interception. Defences include Dynamic ARP Inspection with DHCP snooping on switches, port security, network access control, and encrypting traffic end to end with TLS so intercepted data is useless.

What is the order of volatility in evidence collection?

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Collect the most volatile evidence first because it disappears quickly. The order is CPU registers and cache, memory including running processes and network connections, temporary files, disk, remote logs, and finally archived media. That is why responders capture RAM before shutting down a machine, since malware running only in memory, decrypted keys and active connections are lost at power off.

How do you write an effective security policy?

GRC and ComplianceEasy

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Start from business needs and regulations, keep it short and clear, and state scope, purpose, roles, requirements and exceptions. Avoid technical detail that changes often; put that in standards. Get input from IT, HR and legal, then management approval. Publish it where staff can find it, train people, require acknowledgement and review it at least yearly or after major changes.

What is the role of IAM in AWS security?

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AWS IAM controls who can do what on which resources through users, groups, roles and JSON policies. Best practices are avoiding root account use and protecting it with MFA, using roles with temporary credentials instead of access keys, least privilege policies, permission boundaries, and Service Control Policies in AWS Organizations to set guardrails across accounts. IAM Access Analyzer helps find unused and external access.

What is certificate revocation and how is it checked?

Cryptography and PKIMedium

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Revocation invalidates a certificate before expiry, for example when its private key leaks. Methods are CRLs, which are signed lists of revoked serial numbers, and OCSP, where the client asks a responder about one certificate. OCSP stapling lets the server attach a fresh response to the handshake. Because revocation checking is unreliable, the industry is moving to much shorter certificate lifetimes, which reduces exposure.

What is the Cyber Kill Chain?

Security FundamentalsMedium

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The Lockheed Martin Cyber Kill Chain describes seven stages of an intrusion: reconnaissance, weaponisation, delivery, exploitation, installation, command and control, and actions on objectives. Defenders use it to map controls to each stage, for example email filtering at delivery and egress filtering at command and control. Its weakness is a perimeter focus, so many teams pair it with MITRE ATT&CK for detailed techniques after initial access.

A private key for an internal code-signing certificate was found on a shared drive. What actions do you take?

Cryptography and PKIHard

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Treat it as compromised. Revoke the certificate with the CA, issue a new one with the key generated and stored in an HSM or cloud key service, and restrict signing to the build pipeline. Search for any binaries signed with the old key after the exposure time and investigate them. Remove the file, check drive access logs to see who opened it, and update the key handling policy.

What is the difference between a policy, a standard, a procedure and a guideline?

GRC and ComplianceEasy

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A policy is a high-level management statement of intent, such as all data must be classified. A standard sets mandatory specific requirements, like AES-256 for confidential data. A procedure gives step-by-step instructions to meet the standard. A guideline is recommended but optional advice. This hierarchy lets policies stay stable while standards and procedures change with technology.

GuardDuty reports an EC2 instance communicating with a known crypto-mining pool. How do you respond?

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Isolate the instance by changing its security group to a quarantine group with no traffic, and snapshot its volumes for analysis. Check how it was compromised: exposed SSH, vulnerable app or leaked key. Review CloudTrail for actions by its instance role. Terminate and rebuild from a clean image, rotate secrets the instance could access, and fix the root cause, such as closing public ports.

What are the main containment strategies?

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Short-term containment stops the spread quickly, for example isolating hosts through EDR, disabling accounts, blocking IPs or domains and segmenting networks. Long-term containment keeps business running while preparing clean systems, such as rebuilding servers in a separate network. Responders must balance speed with evidence preservation and avoid alerting a sophisticated attacker too early if they need to understand the full scope.

Which cloud logs are essential for security monitoring?

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Essential sources are control plane audit logs such as AWS CloudTrail, Azure Activity Log and Entra sign-in logs, and Google Cloud Audit Logs. Add network flow logs, DNS logs, load balancer and WAF logs, storage access logs for sensitive buckets, and Kubernetes audit logs. Send them to a central account or SIEM that workload owners cannot delete, and enable threat detection services like GuardDuty.

Tell me about a time you made a mistake at work and how you handled it.

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Situation: as a Tier 1 analyst I closed an alert as false positive without checking the user's later activity. Task: my lead found it was a real phishing compromise. Action: I owned the mistake, helped contain it, and proposed a checklist for credential alerts that includes reviewing activity after login. Result: the checklist was adopted by the shift and similar misses stopped.

What is threat hunting?

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Threat hunting is proactive searching for attackers who evaded existing detections. Hunters start from a hypothesis, for example that attackers use scheduled tasks for persistence, then query EDR and SIEM data to confirm or reject it. Findings become new detection rules. Hunting requires good data retention, knowledge of normal behaviour and frameworks like MITRE ATT&CK to guide hypotheses.

How do you scan your own network for open ports with Nmap, with permission?

Network SecurityEasy

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Only scan networks you own or have written approval for. Start with host discovery, then service and version detection on key ports. nmap -sn 10.10.0.0/24 nmap -sV -T3 -p 1-1000 10.10.0.15 nmap -sV --top-ports 100 -oA scan_results 10.10.0.0/24 Compare results with the approved service list and raise tickets for unexpected open ports.

Tell me about a time you improved a process with automation.

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Situation: our team checked cloud accounts manually every week for public buckets, which took hours. Task: make it faster and continuous. Action: I wrote a small script using the cloud CLI, scheduled it, and sent findings to a team channel with owner tags, then moved it into the CSPM tool. Result: checks ran hourly and average exposure time dropped from days to under an hour.

What is TLS and what does the handshake achieve?

Network SecurityMedium

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TLS secures data in transit. In the TLS 1.3 handshake the client and server agree on cipher suites, perform an ephemeral key exchange such as X25519 for forward secrecy, and the server proves its identity with a certificate signed by a trusted CA. Both derive session keys, then traffic is encrypted with an AEAD cipher like AES-GCM. TLS 1.0 and 1.1 are deprecated and should be disabled.

What is Infrastructure as Code security scanning?

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IaC scanning checks Terraform, CloudFormation, Bicep or Kubernetes manifests for misconfigurations before deployment, such as public buckets or unencrypted databases. Tools include Checkov, tfsec in Trivy, and KICS. It shifts security left, so issues are fixed in a pull request rather than in production. Combine it with policy as code, like OPA, and drift detection to catch manual changes made in the console.

How do you communicate technical incident details to senior management?