How to Conduct an Effective Internal Security Assessment: A Comprehensive Guide
As a cybersecurity professional, I’ve conducted numerous security assessments throughout my career, both external and internal. These audits are crucial for identifying vulnerabilities, ensuring compliance, and strengthening an organization’s overall security posture. In this post, I’ll walk you through the process of conducting an internal security assessment, share some personal experiences, and provide tips to overcome common challenges.
Step 1: Planning and Preparation
Key Activities:
Define the scope of the assessment
Obtain management approval
(Avengers,) Assemble your team
Develop a timeline
Resources:
Common Pitfall #1:
Scope creep — the assessment expands beyond the initial parameters
Solution:
Clearly define and document the scope before beginning. Use a project management tool like Trello, Atlassian (Jira) or Asana to track progress and keep the team focused. I once faced scope creep when assessing our cloud infrastructure. Midway through, management wanted to include on-premises systems. We paused, re-evaluated the timeline and resources, and adjusted accordingly. There’s definitely a need to fret about overcommunicating — it absolutely MUST be done in order to be on the same page about work.
Step 2: Information Gathering
Key Activities:
Review documentation (policies, procedures, network diagrams)
Conduct interviews with key personnel (Calendars, calendars, and more calendars!)
Perform network discovery
Tools:
Nmap for network discovery
Shodan for external asset discovery
Maltego for information gathering
Common Pitfall:
Incomplete or outdated documentation, which may lead to inconsistencies and security concerns
Solution:
Cross-verify information through interviews and technical discovery. While this may make you out to be the bad guy, it’s imperative that you wrangle everyone in and get the facts straight. Document discrepancies for later review, but make sure your notes are as detailed as your thoughts. While conducting auditing assessments, I discovered an undocumented legacy system still in use. This led to a company-wide asset inventory refresh, leading to further discoveries and retirement of various systems (upgrades, too!)
Step 3: Vulnerability Assessment
Key Activities:
Conduct vulnerability scans
Perform manual testing
Analyze results
Tools:
Nessus or OpenVAS for vulnerability scanning
Metasploit for exploitation testing
Burp Suite for web application testing
Common Pitfall:
False positives overwhelming the results
Solution:
Use multiple tools and manual verification to confirm findings. Fine-tuning your tools to reduce false positives or false negatives can make or break the decisions that stakeholders make, since they are typically based on data and statistics. Prioritize vulnerabilities based on risk and exploitability. Initial scans can show thousands of critical vulnerabilities, which is exactly what happened in an assessment I performed recently. After manual verification, we found many were false positives due to outdated plugin databases. No more heart attacks, please.
Step 4: Access Control Review
Key Activities:
Review user access rights
Assess password policies and complexities
Evaluate multi-factor authentication implementation
Tools:
Microsoft Active Directory Administrative Center
AWS IAM for cloud environments
Splunk for log analysis (Or Security Onion if you want to go lean)
Common Pitfall:
Overlooking service accounts or machine-to-machine access.
Solution:
Include all types of accounts in your review. Use automation to regularly audit and report on access rights. We once discovered an ex-employee’s account still had access to critical systems due to a missed offboarding step. This led to the implementation of automated access review processes with human oversight to double-check. Don’t trust your automation 100%!
Step 5: Network Security Analysis
Key Activities:
Review firewall rules
Assess network segmentation
Evaluate intrusion detection/prevention systems
Tools:
Wireshark for packet analysis
Cisco Security Manager for firewall review
SecurityOnion for network security monitoring
Common Pitfall:
Focusing solely on perimeter security and neglecting internal network controls.
Solution:
Adopt a zero-trust approach. Assess both north-south and east-west traffic flows. It’s important that we initially focus on external threats. However, a simulated insider attack can reveal weak internal segmentation, prompting a network redesigns and reconfigurations, as well as overall security infrastructure hardening.
Step 6: Application Security Testing
Key Activities:
Conduct static and dynamic application security testing
Review secure coding practices
Assess input validation and output encoding
Tools:
OWASP ZAP for dynamic testing
SonarQube for static code analysis
Veracode for third-party application testing
Common Pitfall:
Treating application security as a one-time activity rather than an ongoing process.
Solution:
Integrate security testing into the CI/CD pipeline. SAST, DAST, you name it. Provide regular secure coding training to developers and have them work with your security engineers. Collaboration is key.
Step 7: Incident Response Readiness
Key Activities:
Review incident response plans
Conduct tabletop exercises
Assess logging and monitoring capabilities
Tools:
TheHive for incident response management
ELK Stack for log management and analysis
Cymulate for breach and attack simulation
Common Pitfall:
Having an incident response plan that looks good on paper but fails in practice.
Solution:
Regularly test and update your incident response plan. Conduct realistic simulations involving all relevant teams. Conducting red team exercises can reveal gaps in incident response process, leading to improved detection rules and communication protocols.
Step 8: Reporting and Follow-up
Key Activities:
Compile findings and recommendations
Present results to stakeholders
Develop a remediation plan
Schedule follow-up assessments
Tools:
Dradis for collaborative reporting
Jira for tracking remediation efforts
PowerBI for creating executive dashboards
Common Pitfall:
Producing a report that’s too technical for management or too vague for IT teams. Remember, you need to know your audience, and your audience may not have the same technical acumen as you.
Solution:
Create multiple report versions tailored to different audiences. Use clear, actionable language and prioritize findings based on risk. Try to introduce a three-tiered reporting system: an executive summary, a detailed technical report, and a remediation tracker. This can improve communication and increased the remediation rate drastically, leading to reduced confusion.
Conclusion
Conducting an internal security assessment is a complex but crucial process for maintaining a robust security posture. By following these steps, leveraging appropriate tools, and learning from common pitfalls, you can significantly enhance your organization’s security.
Remember, this guide is not exhaustive. There are many ways to get the job done, but we need to ensure that we look at security as an ongoing process. Regular assessments, combined with continuous monitoring and improvement, are key to staying ahead of evolving threats. You wouldn’t just stop locking your doors one day, hoping to be right about the neighborhood safety every day, right?
What challenges have you faced in your internal security assessments?
