Comprehensive Security Follows the Mobile App SDLC

As Cybersecurity Awareness Month 2025 comes to an end, let’s recap what the team at Guardsquare has shared over the last four weeks.

• First, we kicked things off with our summary report on OWASP’s Mobile Application Security project, and how their MASVS verification standards and MASTG guidelines help developers plan, design, and test their projects based on mobile-specific guidance.
• In week two, we shared this video demonstrating how multi-layered code hardening, RASP checks, and polymorphism help ensure an ever-changing defensive posture – making it much harder for attackers to successfully reverse engineer and tamper with mobile apps.
• Week three included a detailed exploration of mobile app threat monitoring. Real-time threat intelligence can transform passive security into an informed defensive system. An adaptive risk management approach combines rapid detection and continuous learning capabilities. This provides both visibility and context, helping developers understand a potential attacker’s behavior and intent.
• Last week, we invited you to watch this on-demand webinar about application attestation, which verifies that the mobile app interacting with your APIs at runtime is authentic, untampered, and trustworthy.

This structure tells its own important story. Comprehensive security for mobile apps must cover the entire lifespan of the application – from their original planning sessions to ongoing version maintenance. Security must also be purpose-built for mobile.

Mobile app usage has been steadily increasing. This means that there's a growing opportunity and attack surface for exploitation, combined with the fact that mobile apps are exceptionally vulnerable. The nature of a mobile application once it’s released into the wild makes it much more susceptible to certain types of risks (such as reverse engineering, tampering, and API abuse) than an analogous web application.

So let’s look at how to secure today’s apps from the ground up by building native security capabilities into the mobile software development lifecycle (mobile SDLC).

Phases of the mobile SDLC

Mobile app developers, security, and DevOps teams tend to have their own customized workflows per organization (or even per project) – but the mobile SDLC can be generally broken into seven phases.

• Plan. The engineering team gathers and analyzes all the requirements that define what the system is supposed to do. This process should include security requirements–both general best practices as well as any specific needs of the customer.
• Design. This typically includes creation of an implementation diagram to outline the basic system architecture and data flows. Threat modeling and security considerations should inform a mobile app’s design. After determining what attack vectors they need to prepare for, software engineers and developers should evaluate protection options that are purpose-built for mobile.
• Develop. Building a mobile app transforms the planning and design into actual code. Even when developers follow secure coding best practices, implementation-specific bugs are a common occurrence at this stage. As such, mobile application security testing (MAST) tools should be integrated within the development environment and continuously used. This includes static code analysis, which performs basic security checks before the code is even committed.
• Test. Code validation is a metric for the security decisions made in the previous phases. The testing approach should include both automated and manual checks that are purpose-built for the unique risk exposures of mobile applications. In addition to ongoing static tests, integrated dynamic analysis tools can test for other types of security issues while the code is running.
• Deploy. When a mobile app is ready for release, security considerations shift to configuration, resilience, and observability. This includes code hardening (multi-layered obfuscation and encryption techniques) to prevent reverse engineering and tampering. Automated runtime application self-protection (RASP) checks injected into the code provide built-in defenses for running mobile apps in the wild. Mobile apps also have some unique susceptibilities to API attacks. This requires dedicated protection through a robust app attestation solution.
• Monitor. Developers need to continuously observe their deployed mobile applications for threat activity or potentially malicious user behavior. Threat monitoring provides real-time visibility and context around things like unusual usage patterns, suspicious activity, and new threat vectors. By monitoring a mobile app’s usage and performance, developers gain real-time insight – enabling them to directly respond to actual threats observed in the wild.
• Maintain. Mobile apps are refined over time for performance, usability, and security through version updates. Monitoring insights and threat intelligence can help developers tune future builds of their mobile apps to keep pace with evolving threats and secure coding best practices.

In most cases, the mobile SDLC itself is continuous and iterative. Maintenance requires a return to planning, design, development, and testing processes – until a new version is ready for redeployment. This cycle repeats until the app is retired. There are several mobile-centric drivers for this hyperactive update cadence.

Technology: Mobile apps exist in a more variable, complex, and codependent world than web apps. This includes an accelerated cycle of new device releases – most mobile users (55.47%) upgrade their phones every two to three years, but about 16% get a new device every 6-12 months. Frequent OS patches and updates cause other downstream impacts for mobile apps. Integrations with other apps and utilities that perform or validate certain functions for the app may also trigger a patch or update. Ongoing maintenance by developers ensures the mobile app remains fully operational within its broader ecosystem.

User retention: Once someone downloads your mobile app, you want them to keep using it. Research shows that 71% of app users churn within the first 90 days of downloading an app. Efforts spent on improving the feature set and functionality (performance and UX) are commonly justified as maintaining user retention.

Security: User retention can also be drastically impacted by app downtime due to an attack or negative publicity from a security incident disclosure or compliance penalty. The threat landscape never sleeps – it’s always evolving. Emerging malware variants, innovative attack techniques, and newly discovered vulnerabilities need to be factored into the ongoing work of mobile app maintenance. Developers and security teams also need to track changes to secure coding best practices, industry standards, and data privacy laws in the regions where their apps are being used. To do all this, they need the right tool at the right time in their pipeline.

Proactive and purpose-built security for the mobile SDLC

Mobile applications need their own dedicated security. Device and OS-level protections do not extend across critical mobile app attack surfaces. Retrofitted or cross-purposed web application testing and protection solutions are not designed for the unique operational nature of mobile applications. Proactive and purpose-built mobile application security engages with each phase of the mobile SDLC.

Mobile app security testing (Design, Develop, Test, Maintain)

To paraphrase Boehm’s Curve, the earlier a security issue is found in the development lifecycle, the less time and cost it takes to fix it. It’s typically easier for a mobile app developer to address a problem when the context of that specific code is still fresh in their mind. But in order to actually do this, developers need the capacity to rapidly identify, analyze, and prioritize critical issues. Tools for continuous integration (CI) help developers by building software every day and making sure it works. Security should be part of CI through automated mobile application security testing (MAST) throughout the design, development, and testing phases before release, as well as during ongoing maintenance as the SDLC repeats.

Protection (Test, Deploy, Monitor)

Once a mobile app is released into the wild, it will be installed by anonymous users on unknown devices that can then travel virtually anywhere in the world. Without multiple layers of built-in protection to preserve the integrity of the original code, a mobile app is vulnerable to reverse engineering and tampering attacks (such as malware injection or malicious cloning to perpetrate account takeover fraud). These unique risks are much more exposed and acute than those facing common web applications. As such, mobile app developers need to incorporate purpose-built protections (which primarily cover the later phases of the mobile SDLC, from pentesting through deployment and monitoring).

Mobile application protection starts with multi-layered code hardening to block static analysis of a reverse engineering attack or attempts by a threat actor seeking to extract secrets or sensitive information related to authentication, transactions, and in-app purchases. An effective solution should use multiple techniques of hiding sensitive code, including name obfuscation, control flow obfuscation, code virtualization, and data encryption.

To counter dynamic analysis attacks, runtime application self-protection (RASP) are built-in security checks within the mobile app code that monitor the app’s behavior in real time and then provide automated defensive responses. These include anti-debugging capabilities that respond to an attack by terminating the app or restricting its functionality. It can provide the ability to block common tampering attacks, like function hooks, dynamic instrumentation, or other code changes. It can take action against tampered system libraries, emulators, virtual environments, and root privileges. RASP can also give a mobile application the ability to defend itself against overlay attacks, a11y abuse, and other malware techniques.

Mobile app attestation (Test, Deploy, Monitor, Maintain)

App attestation is an essential runtime protection for mobile applications because it prevents API abuse by verifying that every frontend app on a mobile device is authentic, unmodified, and running on a secure device. This helps to enforce dynamic security policies that automatically block bots and non-genuine apps from gaining access to backend application resources. An effective app attestation solution not only supports testing and deployment phases, it should also provide security insights during the monitoring and maintenance phases to inform customized policies based on actual threat data.

Both Google and Apple offer OS-based app attestation services to help developers protect their apps. These can reliably detect tampering with the app package on clean devices, but they fall short against more sophisticated real-time attacks.

Threat monitoring (Deploy, Monitor, Maintain, Plan, Design)

After a mobile app is available to download, developers and security teams need real-time visibility to track emerging threats, stay ahead of malicious actors, and limit the impact of an impending attack. Threat monitoring reports should include detailed reasons why a detection was triggered and a clear explanation of the risk. An effective threat monitoring solution should offer real-world validation of information gathered by the application’s RASP checks and app attestation solution to help with protection reinforcement maintenance in those areas. These analytics are also essential to the planning and design of version updates and can even be referenced for development of new mobile apps.

Why Guardsquare?

Organizations shouldn’t have to forgo comprehensive security in favor of development speed or mobile app usability when all three values are essential to their success. Our approach to security covers the full SDLC with solutions that are purpose built for the specific needs of mobile applications and the people who build them.

AppSweep groups MAST findings according to OWASP MASVS for clear vulnerability classification, prioritization, and remediation – enabling developers to prioritize remediation of critical security issues early in the development process.

DexGuard (Android) and iXGuard (iOS) provide comprehensive compiler-based protection for mobile applications. This includes multi-layered code hardening that provides robust mobile app protection against static and dynamic analysis. They also provide advanced RASP capabilities that automatically inject diverse integrity checks throughout the application code. Obfuscation of these RASP checks conceals the boundaries between the application logic and the protection code for reinforced security. Since a unique set of polymorphic defenses is injected with each code compilation, no two protected builds ever look the same. This resets the clock on reverse engineering, rendering any gained knowledge useless with each new build release.

ThreatCast enriches Guardsquare’s protection solutions with monitoring insights that help mobile app developers stay ahead of emerging threats. Malicious behavior like re-signing, code tampering, repackaging, accessibility abuse, or other runtime threats are detected by RASP and securely sent to the ThreatCast server in real time. By relying on ThreatCast data reporting, detailed evidence is collected without compromising the protection of the application. Threat reports deliver incident transparency, including detailed reasons why a detection was triggered and a clear explanation of the risk. These insights can be used for ongoing application maintenance (version updates) as well as planning for new applications.

Finally, Guardsquare’s unique approach to Application Attestation ensures that any mobile app interacting with your APIs and backend systems is genuine. Organizations can detect real-time threats and enforce dynamic security policies, automatically blocking unauthorized access based on aggregated threat intelligence. This server-side validation reinforces an application’s overall protection – complementing the client-side code hardening and RASP measures provided by DexGuard and iXGuard.

Connect with an expert to discuss how Guardsquare can help secure your mobile SDLC.