Network security risk mitigation best practices
This section discusses network security risk mitigation best practices, including least privilege access control, network security monitoring, layered security, and incident response management
Learning objectives
List and describe network security risk mitigation best practices
Develop an appreciation for the need for a layered approach to cybersecurity
Explain the principle of least privilege and its critical role in preventing insider threats and limiting attack surfaces
Differentiate between the functions of IAM (Identity and Access Management), AAA (Authentication, Authorization, and Accounting), and NAC (Network Access Control) in network security
Compare and contrast the goals and methodologies of IDS/IPS and NTA (Network Traffic Analysis)
Outline the four phases of the NIST incident response lifecycle and describe key activities in each phase
Describe the role of automation in ensuring consistent and compliant patch management processes
This section discusses network security risk mitigation best practices, including robust access control (least privilege access control, Identity and Access Management, automated policy enforcement, and Multi-Factor Authentication), network security monitoring, layered security, incident response management, using multiple vendors, Quality Assurance, timely software patching, and physically securing the network.
Topics covered in this section
Robust access control
Least privilege access control
Identity and Access Management (IAM)
Automated policy enforcement
Multi-Factor Authentication (MFA)
Network security monitoring
Network visibility vs network security monitoring
Network security monitoring technologies
Network Traffic Analysis (NTA) vs IDS/IPS
Layered security (defense in depth)
Incident response management
Using multiple vendors
Quality Assurance
Timely software patching
Physically securing the network
Robust access control
A critical aspect of network design is enforcing strict access controls to prevent unauthorized entry. Best practices for access control in network design include least privilege access control, Identity and Access Management (IAM), automated policy enforcement, and Multi-Factor Authentication (MFA).
Least privilege access control: Granting minimal access required for users to perform their duties.
Identity and Access Management (IAM): The core framework for defining and managing identity and permissions.
Automated policy enforcement: The mechanisms that execute the IAM policies. This is the domain of Network Access Control (NAC), automated security group updates, and automated threat response.
Multi-Factor Authentication (MFA): A critical component of IAM. MFA involves mandating multiple verification steps for sensitive systems.
Least privilege access control
The principle of least privilege rules that only the necessary and sufficient level of access privilege is granted to each authorized user or user group. Establishing and enforcing the least-privilege principle for access management and access control is the principal preventive measure against insider threats. Giving users the least amount of access they need to do their jobs enhances data security because it limits what they can accidentally or deliberately access and ensures that if their passwords are compromised, a hacker does not have all keys to the kingdom. It is easier to stay secure by enabling access when needed than to revoke access and mitigate damage after an incident. Network administrators should regularly audit access logs and revoke unnecessary privileges to maintain a least-privilege environment.
Identity and Access Management (IAM)
IAM is a comprehensive system for identification, authentication, authorization, accounting, and identity management. IAM is a comprehensive discipline and set of technologies focused on managing digital identities and their access rights across systems.
IAM is the broad, enterprise-wide strategy for governing identity and access policies. It is responsible for establishing user identities, assigning access privileges, and defining the business rules that govern those privileges across all systems (applications, data, and network). Technologies like Microsoft Active Directory are core components that implement the identity repository aspect of this IAM strategy. AAA is a critical functional framework within IAM, focused specifically on the operational enforcement of Authentication, Authorization, and Accounting for network access. It is the "how" for controlling access to network devices and services. This AAA framework is implemented using specific technologies and protocols. Cisco ISE is a prime example of a comprehensive AAA server that also performs Automated Policy Enforcement. This enforcement is a key capability of modern Network Access Control (NAC) systems, which use AAA protocols like RADIUS and TACACS+ to dynamically apply the broader IAM policies at the network level.
IAM vs AAA
Scope
Enterprise-wide. Covers applications, data, files, cloud services, and network infrastructure.
Network-centric. Primarily focused on controlling access to network devices and network access itself (e.g., Wi-Fi, VPN).
Function
Governance and Strategy. Manages the complete identity lifecycle (onboarding, role changes, offboarding), defines access policies, and ensures compliance.
Operational Enforcement. The specific process of checking credentials (AuthN), granting permissions (AuthZ), and logging activity (Acct) for network access.
Components
Identity Providers (IdP), Single Sign-On (SSO), User Provisioning/De-provisioning systems, Identity Governance tools.
AAA Servers (like Cisco ISE), Network Access Devices (NADs) like switches and WLCs, and protocols like RADIUS and TACACS+.
Analogy
The entire corporate security policy and HR department. It defines that a user is an employee, what their role is, and what resources they should have access to.
The security guard at the building door. They don't decide the policy, but they enforce it by checking your ID badge (AuthN), verifying you're allowed to enter (AuthZ), and noting the time you entered (Acct).
Core capabilities of IAM include:
User Lifecycle Management: Provisioning, de-provisioning, and updating user accounts.
Role-Based Access Control (RBAC): Assigning permissions based on a user's role in the organization. RBAC ensures that users and devices only have permissions necessary for their functions, minimizing insider threats and credential misuse.
Attribute-Based Access Control (ABAC): A more dynamic model that grants access based on attributes (user, resource, environment).
Federation: Allowing users to use a single identity across different systems (e.g., using your corporate login for cloud apps).
Privileged Access Management (PAM): A subset of IAM focused on securing highly privileged accounts.
IAM systems (like Microsoft Active Directory, Azure AD, Okta, Ping Identity) are the source of truth for identity policy.
Automated policy enforcement
IAM defines the policies, users, roles, and permissions. Automated policy enforcement uses the rules defined in the IAM system to automatically allow, deny, or restrict access in real-time. Automated policy enforcement refers to the tools and mechanisms that implement the policies defined in the IAM system without manual intervention. This is crucial for scalability and security in modern networks.
Network Access Control (NAC): A NAC system (like Cisco ISE, Aruba ClearPass, FortiNAC) will:
Check a device's identity - is it a corporate laptop, a guest phone, an IoT sensor?
Check its compliance - is its OS patched? does it have antivirus running?
Query the IAM system - what is this user's role? Sales? Engineering?
Automatically enforce policy: Based on the answers, it places the device on the correct VLAN, grants full internet access, restricts it to only specific applications, or blocks it entirely.
Other examples of automated policy enforcement tools leveraged by IAM include:
Cloud Security Groups and Firewalls: Rules that automatically allow or deny traffic based on security tags derived from IAM roles.
Endpoint Detection and Response (EDR) platforms: Automatically isolating a compromised endpoint from the network based on a policy.
SIEM Automation: A SIEM (Security Information and Event Management) tool automatically disabling a user account after detecting multiple failed login attempts, based on a pre-defined policy.
Network Access Control (NAC)
NAC restricts network access to only those devices that comply with security policies, such as having up-to-date antivirus or OS patches. Non-compliant devices may be blocked, quarantined, or automatically remediated (e.g., by redirecting to a patch server). NAC works best in tightly controlled environments like corporate offices or government networks but can be challenging in dynamic settings like hospitals or universities, where device types and users change frequently, which complicates policy enforcement.
Examples of NAC Technologies:
Open Source:
PacketFence – A widely used open-source NAC that enforces policies via VLAN assignment, captive portals, and device profiling.
FreeRADIUS – A flexible authentication server often integrated with NAC to control network access via protocols like 802.1X.
Commercial:
Cisco ISE (Identity Services Engine) – A leading enterprise NAC solution that enforces policies, profiles devices, and automates threat responses.
Aruba ClearPass – A policy-based NAC platform that supports BYOD, IoT security, and dynamic role-based access.
NAC vs IAM
Network Access Control (NAC) and Identity and Access Management (IAM) are both security frameworks, but they serve different purposes and operate at different layers of IT infrastructure. Here’s how they differ, with concrete examples:
1. Primary Focus
NAC: Controls device access to the network based on compliance (e.g., antivirus status, OS patches).
Example: A hospital blocks an unpatched laptop from connecting to the network until it updates its OS.
IAM: Manages user identities and their access to systems/applications (e.g., logins, permissions).
Example: An employee uses single sign-on (SSO) to access Salesforce but is denied entry to the HR system due to their role.
2. Scope of Enforcement
NAC: Operates at the network layer (ports, VLANs, Wi-Fi).
Tools: Cisco ISE, Aruba ClearPass, PacketFence.
Use case: A university grants students Wi-Fi access only after their devices pass an antivirus check.
IAM: Operates at the application/cloud layer (user logins, APIs, databases).
Tools: Okta, Microsoft Entra ID (Azure AD), Keycloak.
Use case: A contractor can log in to Google Workspace but can’t access the company’s AWS admin console.
3. Key Functions
NAC
IAM
Authenticates devices
Authenticates users
Checks device health (e.g., firewall status)
Manages roles/permissions (e.g., "Read-only" access)
Assigns VLANs or restricts network segments
Enforces multi-factor authentication (MFA)
Often uses 802.1X, MAC filtering
Uses SAML, OAuth, OpenID Connect
4. Overlap & Integration
Modern systems often combine both:
A NAC (like Cisco ISE) might integrate with an IAM (like Microsoft Entra ID) to enforce:
Step 1: Device compliance (NAC) → "Is your laptop patched?"
Step 2: User authentication (IAM) → "Is this employee allowed to use the finance app?"
Example: A bank might use:
NAC to block a teller’s personal tablet from the corporate network.
IAM to ensure the same teller can’t approve transactions in the banking software.
When to Use Which?
Use NAC when you need to:
Secure network ports/Wi-Fi against rogue devices.
Enforce endpoint compliance (e.g., HIPAA-mandated encryption).
Use IAM when you need to:
Manage user access to cloud apps (e.g., SaaS like Slack).
Implement least-privilege access (e.g., "Developer" vs. "Admin" roles).
Multi-Factor Authentication (MFA)
Multi-factor authentication (MFA) requires verification beyond passwords. No matter how secure is a password, there is still a chance it gets into the hands of an attacker. That’s why Multi-Factor Authentication is becoming more and more wide-spread.
Multi-factor authentication involves using at least two authentication methods from at least two of the following categories to prove your identity.
Something you know, for example a username and password combination.
Something you have, for example pressing a notification that appears on your phone using an authenticator app, or using a badge that is scanned.
Something you are, these are unique characteristics about you. For example, biometrics such as a face scan, palm scan, fingerprint scan, retina scan, etc.
Network security monitoring
Network visibility vs network security monitoring
Network monitoring is the practice of continuously observing a computer network for availability, performance, and reliability. Its key goal is to answer the questions: "Is the network operational, and is it performing well?" This is achieved by collecting and analyzing specific, predefined metrics such as device uptime, bandwidth usage, CPU/memory load on routers and switches, and error rates. For example, a network monitoring tool might alert an administrator if a critical server goes offline.
Two concepts that expand upon this foundation are network security monitoring (NSM) and network visibility. NSM focuses on detecting, investigating, and responding to security threats. It uses tools like IDS/IPS and SIEM platforms to analyze traffic for malicious patterns, enforce security policies, and aid in post-incident recovery. While standard monitoring might flag a high bandwidth spike, NSM would investigate if that spike is caused by a legitimate backup or a malicious denial-of-service attack.
Network visibility is a broader, more proactive approach that encompasses both performance and security monitoring. It involves gaining a comprehensive, often granular, real-time understanding of all traffic flows across the entire network infrastructure. This is achieved through advanced telemetry data, flow analysis (NetFlow, sFlow) and packet inspection. Where basic monitoring might track if a link is up/down, visibility reveals which applications, users, and protocols are consuming that link's capacity, providing the essential context needed to troubleshoot complex issues and optimize the network holistically.
Network visibility is the ability to see, understand, and contextualize all activity and data traversing a network. It is not a single tool, but a capability achieved through a combination of tools, processes, and policies. The key pillars of network visibility include:
Knowing what's on your network: All devices, users, and applications.
Understanding behavior: How those devices, users, and applications normally interact.
Identifying anomalies: Spotting deviations from normal behavior that could indicate a problem.
Providing evidence: Having the data to investigate alerts and perform forensics.
Measuring performance: Ensuring the network is functioning as required for business.
Network security monitoring technologies
A secure network design must incorporate robust monitoring to detect and respond to threats in real time. SIEM solutions aggregate and correlate system logs/alerts from IDS, firewalls, endpoints, etc. for centralized threat detection, while endpoint detection and response (EDR) solutions track suspicious behavior across devices for signs of compromise. IDS/IPS solutions help identify/block malicious traffic. Network traffic analysis (NTA) solutions provide visibility into data flows, helping detect lateral movement by attackers.
By integrating these technologies, organizations can proactively identify vulnerabilities and mitigate risks before they escalate.
Intrusion Detection Systems (IDS)
An IDS is a device or software application that monitors a network or systems for malicious activity or policy violations. Any intrusion activity or violation is typically either reported to an administrator or collected centrally using a security information and event management (SIEM) system. A SIEM system combines outputs from multiple sources and uses alarm filtering techniques to distinguish malicious activity from false alarms. (Wikipedia)
IDS types range in scope from single computers to large networks. The most common classifications are network intrusion detection systems (NIDS) and host-based intrusion detection systems (HIDS). (Wikipedia)
A Network Intrusion Detection System (NIDS) is a security mechanism that monitors network traffic for malicious activity or policy violations by analyzing packet headers and payloads, using signature-based detection (known threats) or anomaly-based detection (deviations from baseline behavior). It operates in passive mode, alerting administrators without directly blocking traffic (unlike an IPS). A NIDS can be deployed inline (span port) or via network taps, leveraging protocols like Deep Packet Inspection (DPI) for enhanced threat detection. By comparison, a Host-Based Intrusion Detection System (HIDS) monitors important operating system files. A HIDS is capable of monitoring and analyzing the internals of a computing system as well as the network packets on its network interfaces.
Network Intrusion Detection System (NIDS)
NIDS can be classified based on their detection approach. The primary variants are signature-based detection (identifying patterns associated with known threats, such as exploitation attempts), anomaly-based detection (identifying deviations from a established model of benign traffic, often using machine learning), and reputation-based detection (assessing potential malicious activity based on reputation scores).
A. Signature-Based Detection (IDS/IPS)
Example Tools: Snort (open source), Suricata (open source), Cisco Firepower (commercial)
How it works:
Compares network traffic or system activity against known attack patterns (signatures).
IDS (Intrusion Detection System): Passive monitoring and alerting.
IPS (Intrusion Prevention System): Actively blocks malicious traffic.
Strengths: Effective against known threats, low false positives for well-defined attacks.
Limitations: Struggles with zero-day attacks and advanced threats that evade signatures.
B. Anomaly-Based Detection (Network Behavior Analysis)
Example Tools: Darktrace (commercial), Cisco Stealthwatch (commercial)
How it works:
Uses machine learning or statistical baselining to detect unusual behavior.
Can identify novel attacks but may have higher false positives.
Best for: Detecting insider threats, lateral movement, and unknown attacks.
SIEM (Security Information and Event Management)
The most fundamental approaches to detecting cyber intrusions are to monitor server logs for signs of unauthorized access, to monitor firewall or router logs for abnormal events, and to monitor network performance for spikes in traffic. SIEM can integrate and correlate distributed events and alert on hostile or abnormal behavior.
Example Tools: Wazuh (open source), Splunk (commercial), IBM QRadar (commercial), Elastic SIEM (open core)
How it works:
Aggregates logs from multiple sources (e.g., network devices, cloud services, IDS, servers).
Correlates events to detect complex attack patterns (e.g., multiple failed logins followed by a successful one).
Provides real-time alerting, historical analysis, and compliance reporting.
Strengths:
Holistic visibility across the environment.
Helps with incident response and forensics.
Limitations:
Requires fine-tuning to reduce noise.
Not a direct replacement for IDS/IPS but complements them.
Endpoint Detection and Response/Extended Detection and Response (EDR/XDR)
Example Tools: CrowdStrike (commercial), SentinelOne (commercial), Microsoft Defender for Endpoint (commercial)
How it works:
Monitors endpoint behavior (processes, file changes, registry edits).
Uses behavioral analysis to detect malware and suspicious activity.
Best for: Detecting advanced threats on endpoints/workstations/servers.
Network Traffic Analysis (NTA)
NTA (also called Network Detection and Response, NDR) is a broad process of monitoring network activity to understand what is happening on the network. Its primary goal is visibility and discovery. NTA focuses on analyzing raw network traffic to detect suspicious behavior that evades traditional tools. Network visibility is a practice/capability a level above the more traditional network monitoring. For example, an IDS/IPS might block 99% of the obvious, automated attacks at the perimeter. A NTA solution would then be used to discover the sophisticated, stealthy attacker that bypassed the IPS by finding their unusual command-and-control traffic hidden in normal web requests.
Key Technologies & Tools:
Zeek (formerly Bro): Generates high-level network logs (e.g., HTTP requests, DNS queries).
Suricata (in NTA mode), Zenarmor: Analyzes traffic for anomalies beyond just signatures.
Darktrace, Cisco Stealthwatch: AI-driven anomaly detection (e.g., unusual data exfiltration).
Moloch, Arkime: Packet capture (PCAP) analysis for forensic investigations.
Zeek (formerly Bro)
Open Source/Free
A powerful, widely-used network analysis framework. It is fundamentally a free and open-source software project.
Suricata
Open Source/Free
A high-performance, open-source Network Threat Detection engine (IDS/IPS/NSM). Its core engine is free, though some commercial vendors offer managed services or hardware around it.
Zenarmor
Commercial/Proprietary/Free Edition
A next-generation firewall (NGFW) that provides application control, user/group policies, and web filtering. It is a commercial product built on top of open-source foundations.
Darktrace
Commercial/Proprietary
A market leader in AI-driven network security. It is a purely commercial, proprietary product sold as a subscription service, often with its own appliances.
Cisco Stealthwatch
Commercial/Proprietary
Cisco's enterprise-grade NTA/NDR solution. It is a commercial product that is typically licensed as part of the Cisco ecosystem.
Moloch / Arkime
Open Source/Free
Moloch was renamed Arkime. It is a fully open-source, large-scale PCAP capturing, indexing, and database system.
How NTA Complements Other Tools Example:
A hacker slowly exfiltrates data via DNS
Allows it (DNS is permitted)
Likely misses it (no signature)
Might miss it (unless logs are detailed)
Detects unusual DNS query patterns
Lateral movement via RDP (Remote Desktop Protocol)
Blocks if port is closed
May detect brute-forcing
Logs the event (if logging is enabled)
Flags abnormal internal connections
NTA’s Strengths:
Detects low-and-slow attacks (e.g., data exfiltration, C2 beaconing).
Helps with post-breach investigations (e.g., reconstructing attacker movements).
Works well with encrypted traffic analysis (via JA3 fingerprints, TLS metadata).
NTA's Limitations:
Requires high storage for full packet capture (PCAP).
Can be noisy without proper tuning.
NTA vs IDS/IPS
The network visibility vs network security monitoring dichotomy can be better understood through concrete examples. NTA is more closely related to network visibility, while IDS/IPS is more closely related to network security monitoring.
Network Visibility vs Security Monitoring
Network Visibility (NTA's Goal)
Security Monitoring (IDS/IPS's Goal)
Question it Answers
"What is happening on my network?"
"Is something bad happening on my network?"
Scope
Broad, holistic, contextual
Narrow, focused on threats
Mindset
Proactive, curious, investigative
Reactive, defensive, enforcement
Output
Dashboards, maps, baselines, anomalies
Alarms and Blocks
NTA vs IDS/IPS Summary Table
Primary Goal
Visibility, Discovery, Investigation. To understand normal behavior, find anomalies, and perform forensic analysis.
Detection & Prevention. To identify and stop known attacks and policy violations.
Core Function
Behavioral analysis, baselining, flow analysis (NetFlow, IPFIX), metadata examination, and deep packet inspection.
Signature-based detection, anomaly-based detection, and policy-based blocking.
Focus
Big Picture & Context. "Who talked to whom, when, for how long, and what was the result?"
Specific Events. "Did this packet or stream match a known attack signature?"
Output
Dashboards, maps of network communication, behavioral profiles, alerts on deviations from a baseline.
Alerts (IDS) or Blocks (IPS) on specific malicious activities.
Mindset
Proactive & Investigative. "Let's see what's going on and find what we don't know about."
Reactive & Defensive. "Stop this specific bad thing I know about."
Example
A tool flags that a corporate workstation is sending an unusually large amount of data to a cloud storage service in a foreign country outside of business hours.
A tool blocks a packet because its signature matches the "CVE-2023-1234 Exploit" in its database.
Both NTA and IDS/IPS rely on packet capture and analysis, but they use it in different ways and to different extents.
How NTA Uses Packets:
Full Packet Capture: Some advanced NTA solutions perform full PCAP and store the packets for a period of time. This allows for deep forensic investigation after an alert is generated. You can go back and replay exactly what happened.
Flow Data & Metadata: More commonly, NTA tools analyze network flow data (like NetFlow, sFlow, IPFIX). This is metadata about the traffic (who are the source/destination, what ports, how many bytes/packets, timestamps) rather than the full packet payload. This is less resource-intensive and perfect for building a behavioral baseline.
Statistical Analysis: NTA uses the captured data (both full packet and flow data) to perform statistical modeling to establish what "normal" looks like for every device and user on the network.
How IDS/IPS Uses Packets:
Real-Time Packet Inspection: IDS/IPS engines must capture and inspect packets in real-time. They compare each packet or stream of packets against a massive database of known attack signatures (patterns).
Pattern Matching: The analysis is focused on finding a precise match for a malicious pattern (e.g., a specific string of code in an exploit, a known malicious domain).
Decision & Action: Once a match is found, the system takes immediate action: an IDS will generate an alert, while an IPS will actively drop the malicious packet and block the connection.
NTA for Visibility: The primary value proposition of NTA is to provide deep, contextual visibility into what is happening across the entire network. NTA is focused on Comprehensive Visibility and Behavioral Analysis. It's a tool for learning, investigation, and discovering the unknown. NAT answers questions like:
What is the baseline of "normal" behavior for every device?
How are all the parts of my network connected and communicating?
What are the trends in traffic flow over time?
It's about understanding the environment first and foremost. Visibility is the foundation.
IDS/IPS for security monitoring or threat monitoring: Its job is to constantly scrutinize traffic for threats. IDS/IPS is focused on Targeted Detection and Enforcement. It's a tool for automated alerting and blocking based on known rules and signatures.
How NTA and IDS/IPS Contribute to Visibility
NTA and IDS/IPS are complementary approaches to a robust security posture. Both approaches contribute to the security aspect of visibility.
Both NTA and IDS/IPS contribute to network visibility, but they do so in very different ways, providing different "lenses" to look through.
Network Traffic Analysis (NTA)
Provides a wide-angle, contextual lens. 1. Behavioral Baseline: It first learns what "normal" looks like for every device (e.g., "This server only talks to these three other servers on port 443"). 2. Anomaly Detection: It then flags deviations from that baseline (e.g., "That server is now trying to send data to a new country on a strange port"). 3. Forensic Detail: It often stores packet-level data or rich flow data, allowing you to "rewind time" and investigate exactly what happened during an incident.
A detailed map and a timeline. It shows you all the roads (connections), how much traffic is on them (volume), and can tell you if a car is driving in an unusual pattern, even if it's not breaking a specific law.
IDS/IPS
Provides a targeted, focused lens. 1. Signature-Based Detection: It looks for specific, known malicious patterns (e.g., "This packet contains the exact signature of the latest ransomware"). 2. Policy Enforcement: It alerts on or blocks traffic that violates pre-defined rules (e.g., "Block any traffic from the internal network to known malicious IP addresses"). 3. Point-in-Time Alerts: It provides high-fidelity alerts on specific known bad things, but with less context about the overall environment.
A burglar alarm and a bouncer. It knows the specific faces of known criminals (signatures) and has a list of rules (policies). It screams (alert) or physically blocks (prevent) when it sees a match, but it doesn't necessarily track everyone's movements in the club.
Layered security (defense in depth)
The terms layered security and defense in depth are sometimes used interchangeably to refer to a multi-layered defence architecture or approach. More strictly, defense in depth can be understood as a philosophy or strategy of defence, and layered security as a more concrete operationalization of the defense in depth strategy in the form of technical (procedures) or technological security controls. For example, a stack of firewall, IDS/IPS, SIEM, and EDR could constitute a layered approach to security. But the concept of layered security can be stretched to refer to security domains such as security policies, physical security, network security, endpoint security, application security, and data security.
Defense in depth is an information security strategy that uses multiple layers and types of controls (managerial, operational, and technical/technological) to provide optimal protection.
Defense in depth: the broader, more established term (originating from military strategy) and is widely recognized in cybersecurity as a comprehensive approach combining multiple security layers (technical, administrative, and physical controls).
Layered security: a subset of defense in depth, often referring specifically to the technological controls (firewalls, encryption, endpoint protection, etc.) rather than the full strategy.
Incident response management
One of the biggest challenges facing today's IT professionals is planning and preparing for the almost inevitable security incident.
Incident Response (IR) is a structured methodology for handling security breaches, cyber threats, and policy violations. The goal is to manage the situation in a way that limits damage, reduces recovery time and costs, and prevents future occurrences. A standard IR process follows a lifecycle, often based on the NIST framework (NIST SP 800-61r2: Computer Security Incident Handling Guide) which includes:
Preparation
Detection and Analysis
Containment, Eradication & Recovery
Post-Incident Activity
1. Preparation
This is the proactive phase focused on getting ready for a potential incident before it happens.
What it entails: Establishing a Security Incident Response Team (SIRT), developing and writing an IR plan, acquiring necessary tools (forensic software, communication systems), and providing training through drills and simulations. This phase also includes implementing general security controls to prevent incidents.
The first consideration in an incident response plan is preparation. There should be a manifesto or playbook outlining a structured approach to managing security incidents. Typically an organization should have a SIRT, which will investigate and document incidents. SIRT can be cross functional assembled from various IT related departments or units, and it can be part of or an extension of a SOC team.
The playbook will provision responses commensurate with established risk levels to data assets. For instance, it is important to rank incidents by severity level. It is critical to differentiate between security events (less serious) and security incidents (serious and requiring immediate action). A security event, like a virus on endpoint, might escalate to incident level, but typically it can be addressed via standard procedures or even automation.
2. Detection and Analysis
This is the phase where potential security events are identified and investigated to confirm an incident and understand its scope.
What it entails: Monitoring systems for alerts (from IDS/IPS, SIEM, antivirus), analyzing the evidence to determine the cause, assessing the impact (what systems/data are affected), and prioritizing the incident's severity to allocate appropriate resources.
3. Containment, Eradication & Recovery
This is the reactive core of the IR process where the incident is actively handled and resolved.
Containment: Taking immediate, short-term actions to limit the damage (e.g., isolating a network segment, disabling accounts). This is often split into short-term and long-term containment strategies.
Eradication: Removing the root cause of the incident from the environment (e.g., deleting malware, disabling breached user accounts, addressing vulnerabilities that were exploited).
Recovery: Restoring systems and data to normal operation and confirming they are no longer compromised (e.g., restoring from clean backups, rebuilding systems, bringing services back online).
Organizations should schedule data backups in order to guarantee business continuity in the case of a security incident or disaster. Backups should be created on a yearly, monthly, and weekly basis, and stored in an offsite location. It is critical to encrypt backup data in order to prevent untrusted access to it.
4. Post-Incident Activity
This critical phase occurs after the incident is resolved and focuses on learning from the event to improve future response.
What it entails: Conducting a "lessons learned" meeting to review what happened, what was done well, and what could be improved. This phase results in a formal incident report that is used to update the IR plan, policies, and security controls to prevent a recurrence.
Using multiple vendors
To enhance security, it is best practice to diversify your vendor choices. For instance, when defending against malware, deploy antimalware solutions from different vendors across various layers—such as individual computers, the network, and the firewall. Since a single vendor typically uses the same detection algorithms across all its products, relying on just one provider (e.g., Vendor A) for all three layers means that if one product fails to detect a threat, the other vendor products likely will too. A more effective strategy is to use Vendor A for the firewall, Vendor B for the network, and Vendor C for workstations. This way, the likelihood of all three solutions—each with distinct detection algorithms/methods—missing the same malware is significantly lower than if you depended on a single vendor.
Quality Assurance
Implementing quality assurance (QA) in enterprise information security risk management involves systematically evaluating processes, controls, and policies to ensure they meet defined security standards and effectively mitigate risks. QA aligns with established frameworks like NIST SP 800-37 (Risk Management Framework), NIST CSF (Cybersecurity Framework), and ISO/IEC 27001 by incorporating continuous monitoring, audits, and compliance checks to validate that security controls are functioning as intended. For example, NIST SP 800-37 emphasizes ongoing assessment and authorization, while ISO 27001 requires regular internal audits and management reviews to maintain certification. By integrating QA practices—such as control testing, gap analysis, and corrective action plans—organizations can proactively identify weaknesses, improve security postures, and ensure adherence to regulatory requirements. This structured approach not only enhances risk management maturity but also fosters a culture of continuous improvement, reducing vulnerabilities and strengthening overall information assurance.
Timely software patching
Timely software patching is critical for maintaining a secure network, as unpatched systems are prime targets for cyberattacks. Vulnerabilities in software, whether in operating systems, applications, or firmware, are frequently exploited by threat actors to gain unauthorized access, deploy malware, or exfiltrate data. For example, zero-day vulnerabilities—flaws unknown to vendors until exploited—require immediate patching to mitigate risks. Additionally, compliance frameworks such as NIST, CIS, and ISO 27001 mandate regular patch management to meet security standards. Delayed patching can lead to:
Increased attack surface: Unpatched systems expose networks to known exploits.
Regulatory penalties: Non-compliance with security standards may result in fines.
Operational disruptions: Exploits like ransomware can cripple business continuity.
How Automation Enhances Consistency and Compliance in Patching
Automation is a game-changer in patch management, ensuring patches are deployed promptly and uniformly across an organization’s infrastructure. Manual patching is error-prone and often inconsistent, especially in large or hybrid environments. Automated patch management tools (e.g., WSUS, SCCM, or third-party solutions like Qualys or Tanium) streamline the process by:
Scheduling and deploying patches during maintenance windows to minimize downtime.
Prioritizing critical updates based on CVSS scores or vendor advisories.
Generating audit logs for compliance reporting, proving adherence to regulatory requirements. Automation also enables continuous monitoring for missing patches and rollback capabilities if updates cause instability. By integrating with SIEM or IT service management (ITSM) platforms, automated patching systems can trigger alerts for failed deployments, ensuring no asset is left unprotected. In essence, automation reduces human error, enforces policy adherence, and strengthens overall security posture.
Physically securing the network
To protect an enterprise network from physical threats, organizations must implement robust physical security controls to prevent unauthorized access, theft, or tampering with critical infrastructure. Below are key strategies used in real-world environments:
1. Controlled Access to Facilities
Physical access control protects equipment and data from potential attackers by only allowing authorized users into protected areas such as network closets or data center floors. This is not just to prevent people outside of the organization from gaining access to these areas. Even within the company, access to these areas should be limited to those who need access.
Badge & Biometric Systems – Require employees to use smart cards, key fobs, or biometric scans (fingerprint/retina) to enter secure areas. Multifactor locks can protect access to restricted areas. For example, a door that requires users to swipe a badge and scan their fingerprint to enter. That’s something you have, a badge, and something you are, your fingerprint. Badge systems are very flexible, and permissions granted to a badge can easily be changed. This allows for strict, centralized control of who is authorized to enter where.
Mantraps & Turnstiles – Use double-door entry systems (mantraps) to prevent tailgating and ensure only one person enters at a time.
Visitor Logs & Escorts – All guests must sign in, present ID, and be accompanied by authorized personnel while inside restricted zones.
2. Securing Network Infrastructure
Locked Server Rooms & Cabinets – Critical network devices (servers, routers, switches) should be housed in access-controlled, monitored rooms with rack-mounted locks.
Tamper-Evident Seals – Use security screws, seals, or sensors to detect unauthorized hardware modifications.
Disable Unused Ports – Physically block or disable unused Ethernet, USB, and console ports to prevent unauthorized connections.
3. Surveillance & Monitoring
24/7 CCTV with AI Analytics – Deploy high-resolution cameras with motion detection and facial recognition to monitor sensitive areas.
Security Guards & Patrols – On-site personnel should conduct random checks and verify access permissions.
Environmental Sensors – Monitor for temperature, humidity, and smoke to prevent equipment damage.
4. Preventing Data & Hardware Theft
Asset Tagging & RFID Tracking – Tag all equipment with barcodes or RFID chips to track movement and detect unauthorized removal.
Checkpoint Inspections – Security staff should inspect bags and devices when employees exit the building to prevent data theft.
Secure Disposal Policies – Destroy decommissioned drives (shredding/degaussing) and enforce strict e-waste handling procedures.
5. Redundancy & Disaster Preparedness
Offsite Backup Storage – Keep backups in a geographically separate, access-controlled facility to ensure recovery in case of physical damage.
UPS & Backup Power – Use uninterruptible power supplies (UPS) and generators to maintain operations during outages.
Fire Suppression Systems – Install gas-based (e.g., FM-200) or waterless suppression systems in server rooms to avoid damage from traditional sprinklers.
Enforcement & Best Practices
Regular Audits – Conduct surprise inspections to verify compliance with physical security policies.
Employee Training – Educate staff on social engineering risks (e.g., impersonators) and proper access protocols.
Zero Trust for Physical Access – Apply the principle of least privilege—only grant access to personnel who absolutely need it.
By implementing these measures, enterprises can significantly reduce the risk of physical breaches, insider threats, and unauthorized data exfiltration, ensuring the integrity of their network infrastructure.
Key takeaways
Network security risk mitigation best practices include Identity and Access Management, network monitoring, incident response and disaster recovery, and layered security.
A Layered Defense (Defense in Depth) is Essential: No single security control is perfect. A robust security posture requires multiple, overlapping layers of defense, including technical, administrative, and physical controls.
Enforce Least Privilege and Robust Access Control: Users and systems should only have the minimum level of access necessary to perform their functions. This is a fundamental preventive measure against the spread of attacks and insider threats.
Visibility is the Foundation of Security: You cannot protect what you cannot see. Comprehensive network visibility through monitoring, NTA, and SIEM is crucial for detecting anomalies, investigating incidents, and understanding normal network behavior.
Automation is Key for Scalability and Consistency: Automated policy enforcement and patch management reduce human error, ensure consistent application of security rules, and allow for a rapid response to threats.
Be Prepared to Respond: Having a formal, tested Incident Response plan is critical for managing a security breach effectively to limit damage, reduce recovery time, and learn from the event to improve future resilience.
Security Extends to the Physical World: Network security is not just digital. Physically securing critical infrastructure through access controls, surveillance, and environmental monitoring is a vital part of a comprehensive security strategy.
References
Center for Internet Security (CIS). CIS Controls. Retrieved from https://www.cisecurity.org/controls
International Organization for Standardization/International Electrotechnical Commission (ISO/IEC). (2022). Information security, cybersecurity and privacy protection — Information security management systems — Requirements (ISO/IEC 27001:2022).
Intrusion detection system. (n.d.). In Wikipedia. Retrieved from https://en.wikipedia.org/wiki/Intrusion_detection_system
National Institute of Standards and Technology (NIST). (2012). Computer Security Incident Handling Guide (SP 800-61 Rev. 2).
National Institute of Standards and Technology (NIST). (2018). Risk Management Framework for Information Systems and Organizations (SP 800-37 Rev. 2).
National Institute of Standards and Technology (NIST). (2018). Framework for Improving Critical Infrastructure Cybersecurity (Cybersecurity Framework) Version 1.1.
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