IS Audit Standards & Ethics
ISACA Audit Standards, Guidelines, Code of Professional Ethics, and ITAF Framework
🏛️ ISACA's Information Technology Assurance Framework (ITAF)
ITAF is a comprehensive framework for IT assurance that provides guidance on the conduct of IS audits. It has three components:
- Standards (IS Audit): Mandatory requirements; define minimum performance levels. Auditors MUST comply.
- Guidelines: Provide guidance in applying audit standards. Auditors SHOULD follow.
- Tools & Techniques: Examples and templates to assist in following standards. Auditors MAY use these.
⭐ Three Categories of ISACA Audit Standards
- General Standards (1000 series): Principles guiding the IS auditor's professional behavior — independence, professional care, knowledge/skills, qualifications.
- Performance Standards (1200 series): Describe the nature of IS audit activities and minimum performance requirements.
- Reporting Standards (1400 series): Cover the types of reports, the means of communicating results and the information to be included.
🔑 Key General Standards to Memorize
- Standard 1001 – Audit Charter: The IS audit function shall have an appropriate charter approved by senior management.
- Standard 1002 – Organizational Independence: The IS audit function shall be independent of the area being audited.
- Standard 1003 – Professional Independence: The IS auditor shall be free from all actual or perceived conflicts of interest.
- Standard 1004 – Reasonable Expectation: IS audit function shall have resources with adequate skills, knowledge, and experience.
- Standard 1005 – Due Professional Care: IS auditors shall apply due professional care in all audit activities.
- Standard 1006 – Proficiency: IS auditors shall be competent and maintain their professional competence through CPE.
- Standard 1007 – Assertions: An assertion is a positive declaration. IS auditors rely on management assertions.
- Standard 1008 – Criteria: Audit must have suitable criteria to evaluate the subject matter.
⚖️ ISACA Code of Professional Ethics — 8 Key Principles
- Support the implementation of appropriate standards, procedures and controls for IS.
- Perform duties with objectivity and due diligence.
- Serve the interests of stakeholders in a lawful manner while maintaining high standards.
- Maintain the privacy and confidentiality of information obtained during duties.
- Maintain competence in the interrelated fields of IS auditing.
- Inform appropriate parties of the results of work performed.
- Support the education of management, clients, and the general public.
- Maintain high standards of conduct and character.
🔍 Auditor Independence Types
Independence is fundamental to the IS audit process:
- Organizational Independence: The audit function should be free from interference in its activities by the entity being audited (structural).
- Individual Independence: The auditor should be free from actual or perceived conflicts of interest (personal).
- Appearance of Independence: Others must also perceive the auditor as independent ("independence in appearance").
| Concept | Definition | Key Point for Exam |
| Audit Charter |
Formal document that defines the purpose, authority, and responsibilities of the IS audit function |
Must be approved by Board/Audit Committee; establishes independence |
| Objectivity |
Mental attitude of impartiality in conducting audit work |
Auditor should not audit areas they recently managed (1-year rule) |
| Due Professional Care |
Application of competence and diligence; exercising reasonable care |
Does NOT mean infallibility; means skill of a competent professional |
| Confidentiality |
Information obtained during audit is protected |
Can be disclosed legally if required by law or professional standards |
| CPE Requirements |
Continuing Professional Education |
120 CPE hours per 3-year reporting period, min 20 hours per year |
Audit Planning & Execution
Risk-based audit planning, audit programs, evidence collection, and audit techniques
📋 Audit Planning Process — Step by Step
- Step 1 – Obtain Knowledge of Business: Understand the entity's objectives, operations, and environment.
- Step 2 – Evaluate Prior Audit Results: Review previous audit findings and follow-up actions.
- Step 3 – Identify Audit Universe: All auditable units/areas within the organization.
- Step 4 – Conduct Risk Assessment: Identify and evaluate inherent and control risks.
- Step 5 – Define Audit Scope & Objectives: Determine what will and will not be audited.
- Step 6 – Develop Audit Program: Document specific audit procedures and steps.
- Step 7 – Assign Staff & Resources: Allocate auditors with appropriate skills.
- Step 8 – Address Materiality: Determine significance thresholds for findings.
⚡ Risk-Based Audit Approach
CISA heavily tests this concept. Key relationships to remember:
- Audit Risk = Inherent Risk × Control Risk × Detection Risk
- Inherent Risk: Risk that errors exist before considering controls (nature of the business).
- Control Risk: Risk that controls fail to prevent/detect material errors.
- Detection Risk: Risk that audit procedures fail to detect a material error.
- Higher inherent/control risk → More substantive testing required → Lower detection risk needed.
- Auditors CANNOT change inherent risk but CAN adjust detection risk through testing.
📝 Types of Audit Tests
- Compliance Testing: Tests whether controls exist and are operating as intended. Also called "tests of controls."
- Substantive Testing: Tests the integrity and completeness of transactions/data. Two types:
- Tests of Transactions (walk-throughs, vouching)
- Tests of Balances (analytical procedures, confirmation)
- Key Rule: Compliance testing is performed FIRST. If controls are effective, substantive testing can be reduced.
🔬 Audit Evidence Standards
Audit evidence must possess these qualities (CARS):
- C – Complete: Enough to support the audit conclusion.
- A – Accurate: Free from errors and distortion.
- R – Relevant: Related to the audit objectives.
- S – Sufficient: Adequate in quantity for a reasonable conclusion.
Also: COMPETENT evidence is reliable, valid, relevant, and sufficient.
| Evidence Type | Description | Reliability |
| Physical Observation | Auditor's own observation | High |
| Confirmations | Written responses from third parties | High |
| Documentary Evidence | Internal/external documents | Medium-High |
| Analytical Procedures | Comparison, trend analysis | Medium |
| Inquiry | Oral responses from management | Low |
| Representations | Written management assertions | Low-Medium |
🖥️ Computer-Assisted Audit Techniques (CAATs)
- Audit Software: Used to query, analyze and manipulate data (e.g., ACL, IDEA).
- Test Data: Dummy transactions entered to test processing logic.
- Integrated Test Facility (ITF): Fictitious entity within live system for testing.
- Parallel Simulation: Auditor replicates system processing independently.
- Embedded Audit Modules: Code built into systems to capture transactions.
- SCARF/EAM: System Control Audit Review File — monitors transactions.
📊 Sampling Methods
- Statistical Sampling: Uses probability to select and evaluate results; allows quantitative conclusions about risk.
- Non-Statistical Sampling: Based on auditor judgment; no mathematical precision.
- Random Sampling: Every item has an equal chance of selection.
- Stratified Sampling: Population divided into subgroups; useful when items vary in value.
- Attribute Sampling: Tests whether a control attribute exists (yes/no).
- Variable Sampling: Tests monetary value — used in substantive tests.
Risk Assessment & Internal Controls
Control frameworks, risk assessment methodology, and evaluating control effectiveness
🏗️ Control Frameworks — COBIT 2019
COBIT (Control Objectives for Information and Related Technologies) by ISACA is the primary IT governance and management framework referenced in CISA:
- Governance Objectives (6 EDM processes): Evaluate, Direct, Monitor.
- Management Objectives (35 processes): Align, Plan, Organize (APO); Build, Acquire, Implement (BAI); Deliver, Service, Support (DSS); Monitor, Evaluate, Assess (MEA).
- COBIT aligns IT with business goals and provides metrics for measuring performance.
- Key principle: Governance vs. Management distinction — Board governs; management executes.
🛡️ Types of Controls
- Preventive Controls: Stop errors before they occur. (e.g., access controls, segregation of duties).
- Detective Controls: Identify errors/irregularities after they occur. (e.g., audit logs, exception reports).
- Corrective Controls: Correct errors/irregularities after detection. (e.g., backup recovery, patch management).
- Compensating Controls: Alternative controls when primary controls cannot be implemented.
Exam tip: Preventive > Detective > Corrective is the preferred order. Always prefer prevention.
🔐 Control Categories
- General Controls (IT General Controls): Apply to the IT environment overall — change management, access controls, data center operations.
- Application Controls: Specific to individual applications — input, processing, output controls.
- IT-dependent Manual Controls: Manual controls that rely on IT-generated information.
📐 Risk Assessment Process
- Threat: Potential cause of an unwanted incident.
- Vulnerability: A weakness that could be exploited by a threat.
- Impact: Consequence if the threat exploits the vulnerability.
- Risk = Threat × Vulnerability × Impact
- Residual Risk: Risk remaining after controls are applied.
- Risk Appetite: Amount of risk the organization is willing to accept.
| Risk Response | Description | Example |
| Accept | Acknowledge risk and take no action | Low-impact risk below risk appetite |
| Mitigate/Reduce | Implement controls to reduce likelihood or impact | Firewalls, access controls |
| Transfer | Shift risk to third party | Cyber insurance, outsourcing |
| Avoid | Eliminate the activity causing risk | Discontinue a risky process |
🔑 Segregation of Duties (SoD)
A fundamental internal control concept heavily tested in CISA:
- No single individual should control all phases of a transaction (authorization, recording, custody).
- Prevents fraud and errors by requiring collusion to override controls.
- IT-specific SoD: Systems analyst, programmer, computer operator, data entry, and librarian roles should be separated.
- In small organizations, compensating controls (management review, audit trails) substitute for SoD.
Audit Reporting & ITAF
Communication of audit results, findings documentation, follow-up procedures, and ITAF requirements
📄 Audit Reporting Requirements (ISACA Standard 1401)
- The IS auditor shall provide a report, in an appropriate form, upon completion of the audit engagement.
- The report shall identify the enterprise, the intended recipients, and the restrictions on circulation.
- The report shall state the scope, objectives, period of coverage, and nature/extent of work performed.
- The report shall state the findings, conclusions, and recommendations.
- The report shall state any reservations or qualifications the IS auditor has regarding the engagement.
⭐ Audit Finding Components (CAMP)
Every audit finding must include these elements:
- C – Condition: What IS — the current situation found during the audit.
- A – Criteria: What SHOULD BE — the standard/benchmark being applied.
- M – (Effect/Impact): The risk/consequence of the gap.
- P – (Root) Cause: Why the condition exists.
- Also includes Recommendations for corrective action.
📊 Types of Audit Opinions
- Unqualified (Clean) Opinion: Controls are adequate and effective; no material weaknesses.
- Qualified Opinion: Controls are generally adequate except for specific issues noted.
- Adverse Opinion: Controls are inadequate; material weaknesses exist.
- Disclaimer of Opinion: IS auditor was unable to form an opinion due to scope limitation.
📋 Audit Working Papers
- Working papers document all audit evidence and procedures performed.
- They support the audit findings and conclusions in the audit report.
- Must be complete, accurate, concise, clear and properly indexed.
- Ownership: Working papers are the property of the IS audit function (not management or client).
- Retention period varies — typically 5-7 years based on organizational policy.
- Working papers must be protected from unauthorized access.
🔄 Audit Follow-up Process
- The IS auditor should evaluate whether management has implemented agreed-upon recommendations timely.
- Follow-up Timing: Typically 30/60/90 days after report issuance depending on risk level.
- If management does not implement recommendations, the IS auditor should escalate to appropriate levels.
- Ultimately, escalation goes to the Board or Audit Committee if senior management does not act.
🏢 Audit Committee Role
- The Audit Committee (typically a Board subcommittee) provides oversight of the audit function.
- IS auditors should have direct access to the Audit Committee to ensure independence.
- The Audit Committee approves the audit charter, audit plan, and reviews audit reports.
- Any disagreements between the IS auditor and management should be escalated to the Audit Committee.
| Report Element | Description |
| Title/Date | Identifies the report and when issued |
| Addressee | Who the report is directed to |
| Scope & Objectives | What was audited and why |
| Executive Summary | High-level overview of findings |
| Findings & Recommendations | Detailed issues and suggested actions |
| Management Response | Auditee's response to each finding |
| Auditor Signature/Credentials | Identifies the responsible auditor |