Introduction to the Essential Eight: Why It Matters, Who Needs It, and How It Fits Within the ISM.
It has always been the case but never more so than now that cybersecurity is a necessity. In recent years it has transitioned from broadly a technical concern to a fundamental priority for organisations and businesses. From small enterprises to large government agencies, every organisation faces the same reality: cyber threats are growing in sophistication and scale. At the same time the complexity of our IT environments has made the price of admission much too high for most organisations to reliably defend themselves. To help Australian organisations, large and small, to implement comprehensive cybersecurity, the Australian Cyber Security Centre (ACSC) developed a practical framework known as the Essential Eight.
This blog introduces the Essential Eight, explains why it matters, who it’s designed for, and how it can help guide your organisation’s approach to cybersecurity.
What Is the Essential Eight?
The Essential Eight is a set of eight mitigation strategies designed to protect internet-connected IT environments against a broad range of cyber threats. The E8 provides clear, actionable mitigation strategies that organisations can implement to reduce their risk exposure.
The eight strategies are grouped into three key objectives:
Prevent malware delivery and execution through:
Application control
Patching applications
Configuring Microsoft Office macro settings
User application hardening
Limit the extent of cyber security incidents by:
Restricting administrative privileges
Patching operating systems
Recover data and system availability by implementing:
Multi-factor authentication (MFA)
Regular backups
While each of these strategies provides value on its own, their combined implementation offers layered protection, and the strength of your cybersecurity defences should only ever be considered as strong as your weakest link.
Why the Essential Eight Matters
The E8 matters because it focuses on practical risk reduction. Instead of trying to protect against every possible attack, it addresses the most common and damaging techniques used by cyber adversaries. In the current information technology landscape, it is impossible to protect against every conceivable attack, however it has been made incredibly accessible to defend against the most common attacks with frameworks like Essential 8.
In a world where both complexity and risk have never been higher, the E8 framework provides a clear, evidence-based roadmap to improving security posture without requiring enterprise-level resources.
To summarise, the key benefits of Essential 8 include:
Reduced exposure to common attack vectors
Improved compliance alignment with government standards
Enhanced resilience and recovery capabilities
Clear benchmarking for progress through maturity levels
A clear objective-based framework to demonstrate progress to an organisation.
Who Needs the Essential Eight?
The Essential Eight was initially developed for Australian Government agencies as part of the ACSC’s Information Security Manual (ISM). However, it’s now widely recognized and adopted by a myriad of non-government organisations.
If your organisation handles sensitive information, manages operational technology, or simply wants to demonstrate a commitment to cybersecurity, the E8 provides a scalable and practical foundation.
How the Essential Eight Links to the ISM
The Information Security Manual (ISM) is the Australian Government’s core document for managing cybersecurity risk. It sets out detailed controls and governance requirements for protecting government information and systems. It provides granular, exact requirements in contrast to the broader framework of Essential 8.
Essential 8 does however utilise the ISM to provide specific controls about certain systems and processes to fulfill compliance within its eight strategies. This is incredibly helpful as this provides a direct, actionable list of items that line up to each of the eight strategies.
E8 utilises only parts of the ISM as not all controls are relevant or useful to organisations who may not have the same stringent requirements as confidential government agencies. The controls it does utilise are mapped to levels of compliance within Essential 8 called Maturity Levels. These will be covered later.
To be summarise in a sentence: Essential 8 is the framework, the ISM is the manual.
Understanding Maturity Levels
As environments have varied requirements – what is necessary for an organisation that handles sensitive PII data may not be necessary for a small retail business – it is necessary to separate levels of compliance within Essential 8. Conceptually, you can see Maturity Levels as targets to reach that are implemented iteratively.
The ACSC defines three maturity levels (1–3) and one meta level (0) for each of the Essential Eight controls. These levels allow organizations to assess and measure their implementation progress.
Maturity Level 0:
Controls are not implemented or are ineffective. The organization is vulnerable to common threats.
Maturity Level 1:
Basic controls are in place to defend against opportunistic attacks.
Maturity Level 2:
Controls are regularly applied and integrated into processes to counter more sophisticated threats.
Maturity Level 3:
Controls are fully implemented, enforced, and continuously monitored to defend against advanced persistent threats (APTs).
Maturity Level 0 is not a target but rather an expression of a lack of implemented controls.
Maturity Level 1 is, at minimum, a requirement for any environment regardless of size. It is also a foundational target, so large and small organisations should all begin with aiming for reaching Maturity Level 1 compliance. Larger environments may find that implementation of Maturity Level 1 is not trivial.
Maturity Level 2 and 3 are aspirational and the scope of whether your organisation should target these levels is outside the scope of this article, but in future we will visit the differences between these levels.
Conclusion
The Essential Eight provides a clear, practical foundation for improving cybersecurity resilience across organisations of all sizes. By focusing on the most common and damaging attack methods, it enables businesses to strengthen their defences without unnecessary complexity. E8 translates high-level security principles into actionable, measurable steps that organisations can utilise to navigate a confusing and sensitive concept like cybersecurity. Organisations can progressively assess and improve their cybersecurity posture, starting from essential protections and building toward advanced resilience. The Essential Eight offers a proven, adaptable roadmap to safeguarding systems, data, and reputation in an increasingly hostile digital landscape.