Security Audit

How to select proper standard?

Selecting the proper standard for your organization involves several key considerations:

1. Depth and Breadth: Evaluate how comprehensive the standard is. Some standards cover a wide range of topics but may not go into great detail (breadth). Others may focus deeply on specific areas (depth). Depending on your organization's needs, you might prefer a standard that strikes a balance or one that aligns closely with your specific requirements.

2. Flexibility: Consider how flexible the standard is in its application. Some standards are designed to be applied universally across an organization, while others may be tailored for specific departments or teams. Choose a standard that aligns well with your organizational structure and operational needs.

3. Reasoning and Guidance: Look for standards that provide clear reasoning behind their recommendations and controls. Understanding the rationale behind controls helps in their implementation and auditing processes. This aspect ensures that controls are not only implemented correctly but are also effective in mitigating risks.

4. Prioritization: Assess whether the standard provides guidance on prioritizing risks and controls. This helps in focusing efforts and resources on critical areas that pose significant risks to your organization. Prioritization guidance can streamline your compliance efforts and enhance overall security posture.

5. Industry Acceptance: Consider the level of acceptance of the standard within your industry. Some standards are widely recognized and accepted, which can simplify regulatory compliance and align with industry best practices. Industry acceptance also facilitates benchmarking against peers and demonstrates commitment to security and compliance.

What is Control?

Based on the provided information, "security controls" can be defined as measures or safeguards implemented to mitigate security risks to physical property, information, computer systems, or other assets. These controls are categorized into two main classifications:

1. Goal-based Security Controls:

• Preventive Controls: Aim to prevent security incidents from occurring. Examples include firewalls, encryption, and access control mechanisms.

• Detective Controls: Focus on detecting security incidents after they have occurred. Intrusion detection systems (IDS), security monitoring, and log analysis are examples.

• Corrective Controls: Implemented to mitigate or reverse the impact of a security incident. This could involve data recovery mechanisms, incident response procedures, or system restoration processes.

• Deterrent Controls: Designed to discourage potential attackers or intruders. Visible surveillance cameras, security awareness training, and warning banners are examples.

• Compensating Controls: Alternative measures used when primary controls are not feasible or effective. These controls provide an equivalent level of protection. For example, two-factor authentication might compensate for weaknesses in password-based authentication.

• Common Controls: Applied across multiple ICT (Information and Communications Technology) systems to streamline management and ensure consistent security measures.

1. Implementation-based Security Controls:

• Technical Controls: Utilize technology to enforce security policies and protect systems. Examples include firewalls, antivirus software, and biometric authentication systems.

• Management Controls: Involve administrative or managerial actions to manage risk. Policies, procedures, risk assessments, and security awareness training fall under this category.

• Operational Controls: Implemented and executed by people in their daily operations to ensure security. This includes monitoring, incident response procedures, and access control administration.

What is CAAT?

"Computer-Assisted Audit Techniques (CAATs)" refer to software tools used by auditors, both IT and financial, to evaluate application controls and analyze computerized data for substantive audit tests. These tools are instrumental in assessing the integrity of applications, ensuring compliance with procedures, and monitoring processing results continuously.

Common CAATs like ACL (Audit Command Language) and Interactive Data Extraction and Analysis (IDEA) are utilized to perform various audit tasks such as:

• Selecting a Sample: CAATs can help auditors select random or structured samples from large datasets for audit testing.

• Analyzing Data Characteristics: Tools like ACL and IDEA allow auditors to delve into the characteristics of data files, identifying anomalies or patterns that may require further investigation.

• Identifying Trends in Data: CAATs enable auditors to spot trends or irregularities within datasets, which can be indicative of potential risks or issues.

• Evaluating Data Integrity: These tools assist in verifying the accuracy, completeness, and consistency of data, ensuring its integrity for audit purposes.

Additionally, auditors may utilize other software tools like Microsoft Access and Microsoft Excel for data analysis purposes:

• Microsoft Access: Used for data analysis, report creation, and querying data files. It provides a platform to manage and manipulate datasets efficiently.

• Microsoft Excel: Widely used for data analysis, generating samples, creating visual representations like graphs, and performing statistical analyses such as regression or trend analysis.

CAAT for Sampling

1. Audit Techniques for Sample Size and Selection:

• ACL: Automatically calculates sample sizes based on specified criteria and selects samples from a population of data. This tool ensures that samples are representative and statistically significant for audit testing.

• Spreadsheet Applications: These tools can generate random numbers to aid auditors in selecting samples randomly from datasets. This randomness helps ensure unbiased sampling.

1. Types of Sampling Techniques:

• Judgmental Sampling: Involves selecting samples based on the auditor's knowledge, experience, and judgment. Auditors might choose specific time periods, geographic regions, or functional areas based on perceived risks or significance.

• Statistical Sampling: Involves randomly selecting samples using statistical methods based on probability theory. This approach aims to provide a statistically valid representation of the entire population being audited, minimizing bias and ensuring results are generalizable.

Compliance in User Domain

User Domain Participants:

• Employees: Typically the most trusted users with full access rights to organizational resources and systems.

• Contractors: Have some level of trust with partial access rights, usually limited to specific tasks or areas as defined in their contracts.

• Guests: Least trusted users with very limited access rights, often restricted to external visitors or temporary users.
  

Controls:

• RACI Matrix: Clarifies roles (Responsible, Accountable, Consulted, Informed) for effective project or process management.

• IT-Asset AUP: Defines rules for acceptable use of IT resources to maintain security and operational integrity.

• Internet AUP: Establishes guidelines for safe and appropriate internet usage to mitigate security risks.

• Email AUP: Sets standards for secure and appropriate email communication within the organization.

• HR Security Controls: Ensures security through measures like background checks and access management in the user domain.

Compliance in Workstation Domain

1. Devices: Include UPS (Uninterruptible Power Supply), PC, Laptop, Tablet, Printer, Storage Media, and Smartphone for various work-related tasks.

2. Controls:

• ACLs (Access Control Lists): Manage permissions and restrict access to resources based on defined rules.

• Authentication and Identity Management: Ensure only authorized users access resources through secure authentication methods.

1. Maximizing C-I-A:

• Availability: Achieved through UPS for power continuity and robust backup and recovery strategies.

• Integrity: Maintained by using anti-malware software kept up-to-date to prevent unauthorized modifications.

• Confidentiality: Ensured through access control measures and encryption of sensitive data.

1. Compliance:

• OS Patch Management: Ensures operating systems are updated with security patches to protect against vulnerabilities.

• Application Patch Management: Keeps applications secure by applying timely updates.

• IT Security policy and procedures for workstation: Establishes guidelines for secure usage and maintenance of workstations in alignment with organizational security policies.

Compliance in LAN Domain

• Devices: Include PC, Laptop, Printer, Storage Media, Switch, Hub, Router, and Server (file and printer server) for local network operations.

• Controls:

• Access Control for protected resources: Limits access based on user permissions to ensure security.

• Communication Control to limit malware: Manages network traffic to prevent malware spread.

• Recovery plans including backup for devices in LAN: Ensures data and system recovery capability in case of failures.

• Procedure to control configuration changes: Standardizes and controls changes to network configurations to maintain stability and security.

• Monitoring tools and other detective controls for LAN: Monitors network activity for suspicious behavior or anomalies.

• Software patch management: Ensures all devices are up-to-date with security patches to protect against vulnerabilities.

• Compliance:

• Confidentiality:

• Strong access control: Limits access to sensitive information.

• Encryption: Secures data in transit and storage.

• Privacy policy: Establishes guidelines for handling personal and sensitive data.

• Integrity:

• Anti-malware software installation in all PCs of LAN: Protects against unauthorized modifications.

• Audit the critical data for unauthorized changes: Regularly verifies data integrity through audits.

• Availability:

• Comprehensive recovery plans: Ensures quick restoration of services after disruptions.

• Backup of computers and device configurations: Preserves system configurations and data to minimize downtime.

Compliance in LAN-WAN Domain

1. Devices/Technology:

• Switch, Router, Firewall, Proxy Servers, DMZ (Demilitarized Zone), Honeypots, ISP (Internet Service Provider), IDS/IPS (Intrusion Detection System/Intrusion Prevention System), DLP (Data Loss Prevention).

1. Controls:

• Traffic monitoring and analysis in real time: Monitors network traffic for anomalies or suspicious activity.

• Configuration management: Ensures network devices are configured correctly and securely.

• Change management: Controls and documents changes to network configurations.

• Firewall rules: Defines and enforces rules to control incoming and outgoing network traffic.

• Access rights and Access Controls: Manages user access to network resources based on policies.

• Network Access Control (NAC): Ensures only authorized devices can connect to the network.

• Anti-malware, Firewall status, OS Patch level, Node identity: Monitors and maintains security posture of network devices.

• Vulnerability Assessment and Penetration Testing (VAPT): Identifies and addresses vulnerabilities through testing.

1. Compliance:

• Maximizing C-I-A:

• Availability:

• Redundancy measures like dual homed ISP connections, redundant routers, and firewalls to minimize downtime.

• Business Continuity Planning (BCP) and Disaster Recovery Planning (DRP) for resilience.

• Integrity:

• Use of Virtual Private Network (VPN) for secure remote access.

• Verification of configuration management to ensure integrity.

• Confidentiality:

• Encryption and Data Loss Prevention (DLP) measures to protect sensitive information.

Compliance in WAN Domain

• Devices/Technology:

• WAN Service Provider, Dedicated lines/circuits, MPLS (Multiprotocol Label Switching), WAN L2/L3 switches, WAN backup and redundancy links.

• Controls:

• WAN Optimizer: Improves the efficiency of WAN networks by reducing bandwidth usage.

• Traffic monitoring and analyzer: Monitors and analyzes WAN traffic for security and performance.

• Configuration and change management: Ensures WAN devices are configured securely and changes are managed effectively.

• Access rights and access control: Manages user access to WAN resources.

• VPN (Virtual Private Network): Provides secure remote access to WAN resources.

• Compliance:

• Maximizing C-I-A:

• Availability:

• WAN Service Availability SLAs (Service Level Agreements) to ensure uptime and performance.

• WAN recovery and restoration SLAs for resilience against disruptions.

• Redundancy measures to maintain connectivity in case of failures.

• Backup and recovery plans to recover data and operations in emergencies.

• Integrity:

• WAN traffic encryption and use of VPNs to protect data integrity in transit.

• Confidentiality:

• Compliance with WAN service provider's Security Operations Center (SOC) standards to ensure confidentiality and security.

Compliance in Remote Access Domain

• Devices:

• Remote Users, Remote workstation or laptop, Remote access control tools, Authentication server (TACACS, RADIUS), VPNs (IPSec, L2P, PPTP, L2F) & Encryption, ISP.

• Controls:

• Protection of data privacy: Ensures privacy of data transmitted over remote connections.

• Application data encryption: Encrypts data within applications to prevent unauthorized access.

• Application control encryption (HTTPS): Secures application communication with encryption protocols like HTTPS.

• System connection encryption (VPN): Secures remote connections with Virtual Private Networks (VPN).

• Remote access AUP: Defines acceptable use policies for remote access to company resources.

• Remote access & VPN tunnel monitoring: Monitors and manages remote access and VPN tunnels for security and performance.

• Access configuration, management, rights & control: Manages user access permissions and controls over remote access technologies.

• Compliance:

• VPN Client Definition and Access Controls: Defines and controls access to VPN clients to ensure secure remote connections.

• TLS VPN Remote Access Via a Web Browser: Uses Transport Layer Security (TLS) for secure remote access via web browsers.

• VPN Configuration Management Verification: Verifies and manages VPN configurations to ensure compliance with security policies.

Compliance in System/Application Domain

• Devices:

• Mainframe, Minicomputer, File server, UPS, storage devices, source code, applications, DB (Database), Data center, Backup data center.

• Controls:

• Isolate data: Segregate sensitive data to prevent unauthorized access.

• Limit access to data: Restrict access based on roles and responsibilities.

• Protect data loss through redundancy: Ensure data redundancy and backups to prevent data loss.

• Physical access control: Secure physical access to systems and data centers.

• Environmental control: Manage temperature, humidity, and other environmental factors.

• Fire suppression control: Implement systems to suppress and prevent fires in data centers.

• DR Sites (Disaster Recovery Sites): Establish secondary sites for business continuity in case of disasters.

• Compliance:

• Software configuration management: Manage and control software configurations to ensure integrity and security.

• QA-QT testing (Quality Assurance and Quality Testing): Perform testing to ensure software and systems meet security and quality standards.

• Access rights and access control: Manage and enforce access rights and controls to protect system and application resources.

• Maximizing C-I-A (Confidentiality, Integrity, Availability):

• BCP & DRP (Business Continuity Planning & Disaster Recovery Planning): Plan for continuity and recovery in case of disruptions.

• Drive encryption: Encrypt drives to protect data at rest.

• Vulnerability management: Identify and mitigate vulnerabilities to protect against threats.

• Adherence to the security policy: Ensure compliance with established security policies and procedures.