A Practical Guide to the ASD Essential Eight

The ASD Essential Eight was developed by the Australian Signals Directorate (ASD). This best practice guidance sets out eight key mitigation strategies that, when implemented effectively, can significantly reduce the risk of cyber attacks.

For many organisations, understanding where to start and how to put the Essential Eight into practice can feel daunting. This guide breaks down each strategy into clear steps so you can see how it works in real-world environments.

Why the Essential Eight Matters

Most successful cyberattacks don’t rely on cutting-edge tactics. Instead, attackers often take advantage of common weaknesses such as unpatched systems, unnecessary admin rights, or poor backup practices. The Essential Eight addresses these vulnerabilities directly, giving organisations a clear path to improved resilience. By adopting these strategies, you can lower the likelihood of ransomware attacks, safeguard sensitive data, and demonstrate alignment with recognised cyber security standards.

The Eight Strategies in Practice

1. Application Control

Also known as application whitelisting, this strategy ensures that only trusted and approved software can run on your systems. Without it, malware or unapproved apps can slip through and cause damage.

In practice, this means maintaining a central list of approved applications and blocking executables that aren’t on the list, particularly in temporary folders where malware often hides. The list needs to be reviewed regularly to keep pace with business changes.

Why it matters: attackers often try to trick users into downloading or opening harmful files. By enforcing application control, you block unapproved programs before they can execute, cutting off one of the most common attack paths.

2. Patch Applications

Software vendors release patches to fix vulnerabilities, but if they aren’t applied quickly, attackers can exploit those weaknesses.

To reduce risk, prioritise updates for applications that face the internet, such as browsers, email clients, and Microsoft Office. Aim to apply critical patches within 48 hours and use automated patching tools to reduce manual workload.

Why it matters: many ransomware campaigns succeed simply because a single application was left unpatched. Closing these gaps denies attackers the easy entry points they often rely on.

3. Configure Microsoft Office Macro Settings

Macros can be useful for automating tasks, but they are also one of the most common ways attackers deliver malware through documents.

You can limit this risk by blocking macros from files downloaded from the internet and only allowing digitally signed macros that are essential for business. Staff should also be trained not to enable macros unless they are confident the source is safe.

Why it matters: email-borne threats frequently rely on macros to gain a foothold in an organisation. Restricting their use eliminates one of the easiest and most widely used attack techniques.

4. User Application Hardening

Many applications include features that staff rarely use but that attackers actively exploit. By turning these features off, you reduce the chances of malicious code being executed.

This includes disabling unnecessary functionality in browsers such as Flash, Java, or advertising content, as well as applying security baselines to commonly used programs.

Why it matters: by hardening applications, you shrink the attack surface available to cybercriminals. It becomes much harder for malicious scripts or drive-by downloads to run in the background without detection.

5. Restrict Administrative Privileges

Administrator accounts provide unrestricted access to systems. If attackers manage to compromise one of these accounts, they can disable security controls, install malware, and move freely through your network.

The risk can be reduced by providing admin rights only where they are absolutely necessary, requiring staff to use separate accounts for day-to-day work and administrative tasks, and reviewing privileges regularly.

Why it matters: privilege misuse is one of the quickest ways for attackers to escalate an attack. By restricting admin rights, you contain potential damage and make it much harder for attackers to gain control of your environment.

6. Patch Operating Systems

Like applications, operating systems need regular updates to remain secure. Unsupported or outdated systems are a favourite target for attackers, as they contain unpatched vulnerabilities that are well known and easy to exploit.

Keeping your operating systems current means applying security patches within two weeks of release (or sooner for critical flaws), phasing out unsupported systems, and using centralised patching tools to ensure consistency across the business.

Why it matters: many high-profile breaches can be traced back to an unpatched or outdated operating system. Regular patching is one of the simplest yet most effective ways to stop attackers before they get started.

7. Multi-Factor Authentication (MFA)

Passwords alone are not enough to keep systems secure. Multi-factor authentication adds an additional layer of protection by requiring something beyond a password, such as a code generated by an authenticator app or a hardware token.

MFA should be applied to remote access, privileged accounts, and cloud services at a minimum. Modern authentication methods are far more secure than SMS codes and provide stronger defence against credential theft.

Why it matters: stolen passwords remain one of the most common causes of breaches. MFA ensures that even if attackers obtain a password, they cannot easily gain access without the second factor.

8. Regular Backups

Even with strong defences in place, no organisation is completely immune to attacks or data loss. Reliable backups provide a safety net that allows you to recover quickly if the worst happens.

Effective backups should be automated, stored offline or in a secure cloud environment, and tested regularly to confirm they can be restored in a real-world scenario.

Why it matters: backups do not prevent attacks, but they do limit the damage. With a tested backup process, your organisation can recover operations far more quickly and avoid catastrophic data loss.

Putting It All Together

The Essential Eight is most effective when treated as a complete set of strategies. Each strategy strengthens the others, creating a layered defence that makes it far more difficult for attackers to succeed. For example, patching applications reduces vulnerabilities, while restricting administrative rights limits what an attacker can do if they gain access. Together, these measures form a solid foundation for cyber resilience.

Taking the Next Step

Implementing the Essential Eight is not a one-time exercise. It requires ongoing monitoring, clear governance, and regular reviews to stay effective as both technology and threats evolve.

At Kaon Security, we work with organisations to strengthen their cyber resilience using proven best practice guidance like the ASD Essential Eight. Our team helps you turn the strategies into practical measures that fit your environment, making it easier to close security gaps and prepare for emerging threats.