Mobile applications — especially those handling financial transactions — face platform-specific threats that generic web application testing cannot address. Having tested mobile wallet apps, fintech platforms, and banking applications across multiple countries, we've identified the critical differences between iOS and Android security testing that every development team should understand.
Platform-Specific Attack Surfaces
Android Android's open architecture creates a broader attack surface. APK files can be decompiled and reverse-engineered with readily available tools. We test for hardcoded credentials, API keys in the application bundle, insecure data storage in shared preferences, exported components that expose internal functionality, and custom URL scheme hijacking.
For fintech apps, we specifically test whether transaction-signing keys are stored securely, whether the app properly validates SSL certificates (preventing man-in-the-middle attacks on financial transactions), and whether root detection can be bypassed to run the app in a compromised environment.
iOS iOS provides stronger platform-level security, but implementation flaws remain common. We test for insecure data storage in the Keychain, IPC mechanism abuse, jailbreak detection bypass, and runtime manipulation using tools like Frida and objection.
For fintech apps on iOS, we test whether biometric authentication can be bypassed, whether the app properly implements App Transport Security, and whether sensitive financial data persists in memory after the session ends.
What's Common to Both
Regardless of platform, we test against the full OWASP Mobile Top 10: insecure data storage, insecure communication, insecure authentication, insufficient cryptography, insecure authorization, client-side injection, code tampering, reverse engineering, extraneous functionality, and — critically for fintech — business-logic flaws in payment and transaction flows.
The Fintech-Specific Layer
Beyond standard mobile testing, fintech applications require testing of payment flow integrity, transaction atomicity, concurrent transaction handling (race conditions), offline transaction queuing, and merchant-side payment verification. These tests require deep understanding of financial transaction patterns and cannot be performed by automated scanners.