Application Control: Stopping Unknown and Unauthorised Software Before It Causes Damage

Many cyberattacks succeed not because security tools fail, but because organisations allow too much software to run freely inside their environments.

If any application can execute without restriction, attackers only need one malicious file to gain control. That file might arrive through email, a website, a USB device, or even a trusted tool used in the wrong way.

This is why Application Control is one of the most powerful and preventative controls within the Essential Eight. Instead of trying to detect malicious behaviour after it starts, App Control stops unapproved software from running in the first place.

At Exigo Tech, we see Application Control as a proactive security measure that reduces risk significantly while improving visibility and stability across IT environments.

What Is Application Control?

Application Control is a security approach that allows only approved and trusted software to run on systems. Everything else is blocked by default.

Instead of asking: “Is this file malicious?”

App Control asks: “Is this file authorised to run?”

If the answer is no, the software simply does not execute.

This approach is often called allowlisting. It flips the traditional security model from blocking known bad software to allowing only known good software.

Why Application Control Is So Effective

Traditional antivirus tools rely on detecting known threats or suspicious behaviour. While important, these tools can be bypassed by:

• New or unknown malware.
• Fileless attacks.
• Living-off-the-land techniques.
• Legitimate tools used maliciously.

Application Control reduces this exposure by preventing unknown executables, scripts, and binaries from running at all.

If malicious software cannot execute, it cannot encrypt files, steal data, or spread across systems.

Why Most Environments Allow Too Much Software

Many organisations operate on an open model, where users can install or run almost any software unless it is explicitly blocked.

Common reasons include:

• Convenience and speed.
• Fear of disrupting users.
• Legacy practices.
• Lack of visibility into installed applications.
• No formal software approval process.

Over time, this leads to environments filled with unapproved tools, outdated software, and inconsistent configurations, all of which increase risk.

Why Application Control Is Essential Eight–Critical

The Essential Eight focuses on preventing attackers from gaining control inside systems. App Control directly supports this objective by limiting what can run in the environment.

Even if:

• A user clicks a malicious link.
• A phishing email delivers a harmful file.
• An attacker gains initial access.

Application Control prevents unapproved code from executing.

This dramatically reduces the likelihood of ransomware and other malware successfully launching.

What Happens Without Application Control

When Application Control is not in place:

• Users may unknowingly run malicious software.
• Attackers can execute scripts to escalate privileges.
• Malware can spread rapidly across devices.
• IT teams must rely on detection rather than prevention.

In many ransomware incidents, attackers successfully executed tools that were not blocked because there were no restrictions in place.

Prevention is always more effective and less costly than response.

Benefits of Implementing Application Control Properly

When Application Control is implemented thoughtfully and consistently, organisations see measurable improvements.

• Reduced Likelihood of Malware Execution

Only approved applications can run, blocking many common attack paths.

• Lower Ransomware Risk

Ransomware often relies on executing unapproved files. App Control stops that process early.

• Improved System Stability

Unapproved or unstable software is prevented from affecting systems.

• Greater Visibility into Software Usage

IT teams gain clearer insight into what applications are being used across the environment.

• Stronger Compliance and Audit Readiness

Application allowlisting is widely recognised as a strong preventative control.

• Reduced Incident Response Burden

Fewer successful attacks mean fewer investigations and recovery efforts.

• Increased Executive Confidence

Leadership can be confident that only authorised software is operating within the organisation.

Common Mistakes Organisations Make with Application Control

Application Control is powerful, but it must be implemented carefully.

Common mistakes include:

• Blocking too aggressively without testing.
• Failing to document approved software.
• Not accounting for updates and new versions.
• Allowing broad exceptions that weaken the control.
• Treating it as a one-time configuration rather than an ongoing process.

Poor implementation can frustrate users and undermine the effectiveness of the control.

What Good Application Control Looks Like

Effective Application Control balances security with usability.

Good implementation includes:

• Creating an approved software baseline.
• Testing in phases before full deployment.
• Establishing a clear approval process for new software.
• Monitoring for attempted unauthorised execution.
• Reviewing and updating allowlists regularly.

The goal is to protect systems without blocking legitimate work.

Why Application Control Improves More Than Just Security

Beyond cybersecurity, Application Control supports:

• Standardised IT environments.
• Easier troubleshooting.
• Reduced software sprawl.
• Lower licensing risks.
• Improved operational consistency.

It creates cleaner, more predictable systems, which benefits both IT teams and users.

Why Choose Exigo Tech to Implement Application Control

Application Control requires planning, oversight, and continuous tuning.

As your Managed Intelligence Partner, we:

• Assess your current software exposure.
• Design a controlled and practical allowlisting strategy.
• Implement phased rollouts to avoid disruption.
• Establish approval and governance processes.
• Continuously review and refine the environment.

We ensure App Control strengthens security without becoming an operational burden.

Application Control Is About Prevention, Not Reaction

Many organisations invest heavily in detecting attacks after they occur. Application Control shifts the focus to prevention.

By limiting what can run inside your environment, you dramatically reduce the opportunity for attackers to succeed.

That is why App Control remains one of the most impactful and preventative measures in the Essential Eight framework.