Thick Client Testing

Desktop application testing for the local logic, protocol behavior, and trust assumptions that attackers target directly

We assess binaries, update behavior, storage, transport, and backend trust assumptions to uncover how a local foothold or tampered client could drive larger impact.

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What teams usually value in this service

Binary and protocol-level review

Client-to-server trust validation

Remediation guidance for desktop teams

What is covered

Local storage, secrets, and offline trust decisions
Custom protocols, serialization, and client-server message handling
Update paths, patch behavior, and integrity assumptions
Privilege assumptions in local workflows and executable logic
How backend systems trust signals coming from the client

Who this service is for

Teams shipping desktop applications with privileged workflows or sensitive data handling
Organizations relying on thick clients for internal or operational systems
Products where protocol tampering or local logic abuse could affect central systems

Common attack paths and issues tested

Local logic abuse

We test whether critical decisions are made in the client where they can be bypassed, modified, or replayed.

Protocol tampering and unsafe serialization

Custom transport and message formats are assessed for trust gaps, injection, and unsafe deserialization behaviors.

Update and integrity path weakness

We review how the application updates, validates packages, and protects against tampered or downgraded binaries.

What clients receive

Findings mapped to client behavior, backend trust, and operational impact
Clear guidance for desktop engineering and platform teams
Evidence that supports remediation tracking and customer review if needed
Retest support after fixes

Engagement process

1Define client workflows, backend dependencies, and threat priorities
2Assess the binary, local behavior, and communication patterns
3Validate exploitability and realistic impact paths
4Provide reporting, walkthrough, and retesting

Related resources

Articles that help teams evaluate and prepare for this service

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Pentest Methodology• 4 min read

What a Real Penetration Test Should Include

A real pentest should validate exploit paths, business logic, and impact. It should not stop at scanner output or generic severity labels.

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Compliance / Buyer Security• 4 min read

What Enterprise Buyers Expect in a Pentest Report

Enterprise buyers want more than proof that testing happened. They want evidence the work was credible, risk was understood, and remediation can be tracked.

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Frequently asked questions

Is thick client testing different from web app testing?

Yes. Local execution, protocol handling, and update mechanisms create risks that are not visible in a browser-based assessment.

Do you need source code?

Not necessarily. A build, installer, and test environment are often enough to perform an effective black-box or gray-box review.

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