Cybersecurity Specialist Interview Questions

I start by scoping the assessment carefully: what assets are in scope, what the business impact of downtime would be, and what maintenance windows are available. I use a combination of automated scanning tools like Nessus or Qualys to identify known CVEs, then follow up with manual verification to cut false positives. For production systems I prioritise read-only, non-disruptive checks first and schedule any active testing during low-traffic windows with the operations team informed. After scanning, I triage findings by CVSS score and business context, because a critical score on an internal-only system is a different risk than the same score on an internet-facing API. I document everything in a remediation report with clear ownership and timelines, not just a raw list of findings.

I have worked with Splunk and Microsoft Sentinel in production environments, and with QRadar in a lab setting. Alert fatigue is one of the biggest practical challenges in any SOC. My approach is to tune at the source: I review alert rules quarterly and suppress or adjust any rule that has generated zero true positives in 90 days. I also build correlation rules that group related low-fidelity alerts into a single higher-confidence incident rather than flooding the queue with individual events. For new environments I start by baselining normal traffic for two to four weeks before enabling threshold-based alerts, so the baselines reflect real behaviour rather than generic defaults. I track false positive rates per rule in a simple dashboard so the team can see which rules need attention.

I follow several threat intelligence feeds: the CISA Known Exploited Vulnerabilities catalogue, vendor advisories from Microsoft and CrowdStrike, and community sources like SANS Internet Storm Center. I subscribe to weekly digests from Krebs on Security and The Hacker News for broader context. Within my team, I run a short monthly session where we review one recent real-world breach or CVE together and discuss what controls would have caught or limited it. I also participate in CTF competitions a few times a year, which keeps my practical skills sharp in areas like reverse engineering and web exploitation that do not come up in day-to-day work. Staying current is not just personal: I document relevant threats in our internal knowledge base so the whole team benefits.

At my previous role, our SIEM fired an alert at 11pm on a Friday showing unusual outbound traffic from a domain controller to an unfamiliar external IP. I was on call. I immediately isolated the affected machine from the network to contain the potential spread, then pulled the relevant logs from Splunk covering the previous 48 hours. Within 20 minutes I identified that a service account had been used to run PowerShell commands that exfiltrated a directory listing to an external endpoint. I escalated to the security manager and opened a formal incident ticket. We traced the initial access to a phishing email that had delivered a macro-enabled document three days earlier. I coordinated with IT to reset credentials, patch the vector, and run a full scan of similar endpoints. The incident was contained within four hours. The post-mortem led us to block macro execution across all endpoints, which we had not done previously.

During a routine internal penetration test I discovered that an older internal web application was vulnerable to SQL injection on its login endpoint. The app was still processing HR data for around 400 employees. I immediately stopped testing to avoid unintentional data extraction and documented the exact payload and response that confirmed the vulnerability, with screenshots, so the development team had clear reproduction steps. I escalated to both the application owner and the CISO that same afternoon via our vulnerability disclosure process, flagging it as critical. I recommended taking the application offline temporarily while a patch was prepared, which they agreed to. I worked with the developer to test the fix in staging and then validated the patch in production the following day. The whole cycle from discovery to verified fix took 36 hours. I also flagged that several other legacy apps likely had similar issues and proposed a targeted audit, which was approved.

I was tasked with rolling out multi-factor authentication across all cloud environments. One of the engineering teams pushed back hard, arguing that MFA on their CI/CD pipeline service accounts would break their deployment workflow. Rather than escalating immediately, I scheduled time with their tech lead to understand the specific friction. It turned out their concern was legitimate: their tooling did not support interactive MFA prompts in automated pipelines. I researched alternatives and proposed using short-lived service account tokens with strict IP allow-listing and automated rotation via HashiCorp Vault as a compensating control, documented against our ISO 27001 gap register. I presented this to the CISO as an accepted risk with a defined compensating measure, and the engineering team appreciated that I had taken their constraint seriously. The result was full rollout across interactive accounts within two weeks, and a clear roadmap to migrate the pipeline accounts once their tooling supported it.

Authentication is the process of verifying who a user or system is. Authorisation is the process of determining what that verified identity is allowed to do. They are distinct controls and failures in each have different consequences. A broken authentication vulnerability means an attacker can impersonate a legitimate user entirely. A broken authorisation vulnerability means an attacker who is already authenticated can access resources or perform actions they should not be able to, such as accessing another user's data by changing an ID in a URL. In security design, you need both: strong authentication using MFA, secure session management, and credential hashing, combined with a well-defined authorisation model using role-based or attribute-based access control. A common mistake is assuming that authentication is sufficient: many real-world breaches involve valid credentials used to reach data that should have been access-controlled but was not.

I break a penetration test into five phases. First, scoping and rules of engagement: I agree with the client on what is in scope, what is off-limits, what testing methods are permitted, and who to call if something goes wrong. Second, reconnaissance: I gather open-source intelligence using tools like Shodan, Amass, and theHarvester to map the attack surface before touching anything. Third, scanning and enumeration: I use Nmap for port and service discovery, then more targeted tools depending on what I find. Fourth, exploitation: I attempt to exploit identified weaknesses, always within the agreed rules, and document what I access, not just that I got in. Fifth, reporting: I write a report structured around business risk, not just technical findings. Each finding gets a severity rating, evidence, business impact, and a specific remediation recommendation. I always debrief the client in person before the written report so they are not reading about critical findings cold.

Phishing is the most common initial access vector. Defence starts with technical controls: email filtering, DMARC and SPF configuration, and blocking macro execution in Office documents. But the most durable defence is security awareness training with regular simulated phishing exercises. SQL injection occurs when user input is inserted into database queries without sanitisation. The primary defence is using parameterised queries or prepared statements: this makes injection structurally impossible. Output encoding and a web application firewall add further layers, but parameterised queries are non-negotiable. Man-in-the-middle attacks target data in transit, typically on unsecured networks. The defence is enforcing TLS across all connections, implementing HSTS headers, using certificate pinning for mobile applications, and educating users not to connect to public Wi-Fi without a VPN. Each of these defences is most effective when layered: no single control stops a determined attacker, but the combination raises the cost of an attack significantly.