These payment apps are an attractive prospect, as a single compromise can result in direct monetary loss, with the theft of UPI PINs, bank accounts and sensitive identity details. Attacks have gotten beyond the static code, now attacking the live execution environment through dynamic instrumentation, memory scraping, and malicious overlays. Traditional vulnerability scanning is simply not fast enough for these attack vectors that target mobile applications.
While it is important to identify vulnerabilities before deployment, it is vital to detect attacks at runtime through ongoing defense. This article explores why it is essential to secure the entire mobile application attack surface is more than just a static check, why payment applications need continuous security protection and the steps CISOs need to take to stop real time fraud.
What Is Mobile App Security Testing?
Mobile application security testing is the systematic process of testing an application for the existence of flaws, weaknesses and misconfigurations that can be exploited by an attacker. The main reason for this testing is to guarantee that the weaknesses of mobile applications are addressed before reaching the end user.
It generally includes:
Static Application Security Testing (SAST): Examination of source code, without running an app, to look for static code patterns, hardcoded secrets and known vulnerabilities.
Dynamic Application Security Testing (DAST): Testing application for runtime vulnerabilities.
Manual security testing: This checks for penetration of mobile devices by ethical hackers to uncover vulnerabilities in the devices in order to simulate real-world attacks.
API security testing: Verifying the API's connection with the back-end servers.
Run-time security testing: Testing for active threats as the app is running.
Vulnerability Assessment: Automated scanning of APK/IPA files, configurations and encryption implementations.
The Traditional Approach
Conventional mobile app security testing commonly focuses heavily on pre-deployment checks. Security teams analyze source code, conduct APK/IPA analysis, review configuration issues, and assess encryption implementations.
However, finding vulnerabilities before deployment is important, but it does not fully protect a payment application while it is running on a potentially compromised mobile device. In fact, a September 2026 advisory from the Reserve Bank of India (RBI) emphasized that foundational weaknesses remain rampant, urging banks to look beyond static defenses. When an application operates in the wild, static defenses cannot stop active tampering or memory manipulation.
Why UPI & Payment Apps Need Specialized Security Testing?
Payment applications have specific security needs, as they are used to process financial transactions, which are often significant in value. An exploit in the gaming application could reveal an email address, and an exploit in the payment application could empty a bank account.
They handle extremely confidential data like UPI IDs, bank account details, payment credentials and buyer identity details. Payment apps take care of transaction authorisations via delicate APIs and routinely use intricate third party integrations for analytics or fraud scoring. In addition, they have to face real-time fraud and device-level threats as many of these apps may be installed on consumers' outdated or malware-infested smartphones.
In order to appreciate the size of the target ecosystem, think of the huge number of transactions that are processed every day in the country. Companies developing these infrastructures need to implement a range of security measures and deploy specific mobile payment security testing methods to ensure digital payment security at scale.
Why Traditional Mobile App Security Testing Is Not Enough?
The traditional testing approach will still be able to detect static structural weaknesses, but it will not be adequate to solve attacks on a dynamic basis. Mobile payment applications are deployed in an inherently untrusted environment – the user's personal device.
Traditional vulnerability scanners are based on code at rest, but modern threat actors will run attacks:
During application execution.
When a phone is compromised (rooted or jailbroken).
Against Application memory for extracting cryptographic keys.
Using instrumentation frameworks, such as Frida or Xposed.
By repackaged clones and packages with modifications.
By fraudulent over-lays to steal credentials.
By changing the value of transactions at runtime.
By using certificate-pinning bypass techniques.
By exploiting the business logic.
By using proper features in a dishonest way.By exploiting legitimate features for fraud.
Main message: Testing reveals vulnerabilities. A powerful mobile runtime protection is used to protect the application when these weaknesses are actively exploited.
10 Mobile Payment App Attack Surfaces Traditional Testing Can Miss.
These are the 10 attack surfaces that security teams need to assess for a comprehensive mobile application security evaluation.
1. Runtime Manipulation
Instruments the code at runtime and hooks methods to steal function calls, allowing to change the behavior of the application or manipulate its memory at runtime. Static analysis can not detect run time manipulation as the underlying code has not been changed.
Security Controls: Runtime threat detection, RASP for mobile applications, application integrity checks, anti-hooking controls.
2. Certificate Pinning Bypass
The idea behind certificate pinning is to make it impossible to implement a Man-in-the-Middle (MITM) attack by hardcoding the SSL certificate for the server into the App. The attackers try to bypass the certificate pinning by leveraging runtime interception frameworks to get the app to accept fake certificates. It is important to note that implementing it might not be sufficient to prevent this in a production setting.
Security Controls: Certificate validation and runtime detection, Application integrity and Anti-instrumentation.
3. Code Tampering
Threat actors download the legit app, decompile it, inject malicious modifications, and repack it into an app that will steal data.
Security Controls: Applying code obfuscation, anti-tampering, signature validation and mobile application integrity protection.
4. Reverse Engineering
APK/IPA decompilation is used by the attackers for business logic discovery, API discovery, and credential/secret discovery. This can result in significant IP exposure and give back to attackers a path to vulnerabilities in the backend system.
Security Controls: Code obfuscation, anti-debugging, mobile app code protection and secure secret management.
5. Deep Link Abuse
Application routing is determined by deep links and universal links. These flaws in deep linking security are exploited by attackers to obtain malicious redirection, which causes unexpected actions or potential risks for authentication.
Security Controls: Input validation, domain validation, secure routing and strict authorisation checks.
6. Inter-Process Communication (IPC) Attacks
Malicious apps can communicate with one another on the same device via Android IPC, Intents, and exported components, exposing critical functionality. Ensuring proper IPC security is paramount.
Security Controls: Secure component configuration, permission controls, input validation, runtime monitoring.
7. WebView Attacks
Unsafe JavaScript interfaces and insecure WebView configuration can lead to malicious content getting loaded, interception of web-to-native communication, and data exposure. Security in WebView is an important component of the overall application security.
Security Controls: Secure WebView configuration, URL allow listing, input validation and run time monitoring.
8. Third-Party SDK Risks
Payment apps of today use open-source components, payment SDKs, analytics SDKs, and authentication SDKs. Security testing should not only be done against first party code; one vulnerable SDK can make the entire app vulnerable.
Security Controls: Dependency monitoring, SDK assessment, Software Bill of Materials (SBOM), and continuous runtime threat detection.
9. Overlay Attacks
Banking Trojans use malicious overlays to trick users into entering their payment information, deceive users by showing a UI that looks like a payment app, and manipulate the transactions.
Security Controls: Overlay detection, Device integrity checks, Mobile application runtime protection, and Risk-based authentication.
10. Business Logic Abuse
Attackers use legitimate API, spoofing attacks and manipulate parameters in order to run sophisticated fraud scenarios and bypass authorizations. Legitimate application workflows may be complex and traditional mobile app vulnerability assessment tools may not have a deep understanding of them to detect these logical flaws.
Security Controls: Business logic testing, API security, transaction monitoring and vulnerability management.
Static vs Dynamic Mobile App Security Testing
A mature mobile application security assessment requires diverse testing methodologies.
Security Approach | What It Identifies | Limitations |
SAST | Source-code vulnerabilities | Limited runtime visibility |
DAST | Runtime/application behavior | May not identify deeper code-level issues |
Mobile Pen Testing | Exploitable weaknesses | Point-in-time assessment |
API Testing | API vulnerabilities | Does not protect the complete client runtime |
Reverse Engineering | Code and logic exposure | Assessment is generally periodic |
Runtime Protection | Active runtime attacks | Requires deployment and continuous monitoring |
Key Takeaway: A mature security strategy should combine testing and runtime protection rather than treating them as alternatives.
Why Runtime Protection Matters for UPI & Payment Apps?
Payment apps are installed on devices which IT departments have no control over. Static defenses are easily bypassed as attackers can change the runtime environment, and the application can be instrumented. Attackers may try to circumvent security measures actively, whereas static testing occurs prior to deployment and runtime attacks occur after deployment.
Run-time Application Self-Protection (RASP)
Financial institutions need to employ RASP (Runtime Application Self-Protection) for protection against active threats. A strong mobile RASP solution will offer automated response functionality, which will make sure that mobile app runtime security is maintained. Features include real-time attack detection, mobile app anti-tamper, anti-debugging, root/jailbreak detection, hook detection, and maintaining application integrity. This transforms runtime security into an active shield, not a passive checklist.
Mobile App Security Testing Approach for UPI Applications
An enterprise's teams should follow the following framework for mobile app vulnerability testing.
Step 1: Threat Modeling
Architecture mapping is the first step in security pre-testing. Determine core payment flows, authentication methods, sensitive APIs, sensitive data storage, device risks and all third party integrations.
Step 2: Perform Static Analysis
Run SAST to analyze the code base. Test first party code and third party dependencies, hardened secrets, Android/iOS permissions, encryption standards, and overall security configurations.
Step 3: Do Dynamic Testing
See how the application works in action. Ensure that logs don't expose sensitive data by testing runtime behavior, API interactions, session authentication, request authorization, and data flow.
Step 4: Also Do Mobile Penetration Testing.
Deploy ethical hackers to conduct mobile app penetration testing. Attack vectors checked for include: MITM attacks, deep links, authentication bypass, tampering, the WebView, IPC security, and reverse engineering resilience.
Step 5: Run Runtime Security Tests
Conduct mobile runtime security tests to ensure that defensive controls are effective. Instrument, hook, debug, test in a root/jailbreak, code inject and manipulate in runtime.
Step 6: Apply Continuous Protection
A vulnerability evaluation is a single snapshot in time, so put in place continual defenses. Implement runtime monitoring, active threat detection, application integrity verification, responsive action activation and rich threat intelligence.
Common Mobile Payment App Vulnerabilities
Failing to conduct rigorous testing often leads to pervasive mobile payment vulnerabilities:
Insecure data storage
Weak authentication
Broken authorization
Insecure APIs
Code tampering
Reverse engineering
Runtime manipulation
Certificate pinning bypass
WebView vulnerabilities
IPC vulnerabilities
Deep-link vulnerabilities
Overlay attacks
Third-party SDK vulnerabilities
Business logic vulnerabilities
API abuse
Addressing these UPI app vulnerabilities requires a combination of robust testing and proactive runtime defense.
Mobile App Security Testing for Major UPI & Financial Applications
There are many large UPI and financial applications where mobile app security testing is absolutely necessary.
The same security concepts are needed throughout India's growing UPI, banking, lending and investment applications landscape. No matter if an organization is creating a new wallet or improving a legacy platform, the security of the ecosystem is of utmost importance.
UPI & Payment Applications
The standards imposed by the secure landscape of the PhonePe mobile app and the good security of Google Pay come to be the standards of the industry. Paytm app security and BHIM app security help millions of people to conduct sensitive transactions every day. Moreover, platforms that are a mix of e-commerce and payments have to emphasize on the security of Amazon Pay, whereas regional leaders give a lot of importance to securing their user base with the help of MobiKwik app security and BharatPe app security. Protecting every node in this varied network is key to ensuring secure UPI applications.
Banking Applications
Traditional banks are now fully mobile-first. For HDFC Bank mobile app security, ICICI Bank mobile app security, and Axis Bank app security, users are looking for comprehensive threat modeling to ensure their financial transactions are secure. It is important to enforce rigorous penetration testing for Kotak Bank app security, IDFC FIRST Bank app security, and Yes Bank app security, to maintain digital payment security. The standard is universal, and advanced RASP will safeguard Federal Bank application security and RBL Bank application security against new threats.
Applications in Fintech, Lending & Investment.
Financial portfolios are very sensitive and go in and out of the hands of modern wealth management and lending platforms. Fintech application security testing needs to uncover logic vulnerabilities to address Navi app security, KreditBee app security, Groww app security. To ensure financial fraud, deep dynamic analysis is necessary to ensure trust in CRED app security, Bajaj Finserv app security. Moreover, a comprehensive fintech mobile security platform is needed to secure the underlying infrastructure.
Best Practices to Secure UPI and Payment Apps
To ensure full mobile app security, the following practices should be employed:
Enforce secure coding guidelines and APIs.
Require strong authentication and authorization using MFA.
Use encryption to protect data at rest and during transmission.
Use certificate pinning to prevent man-in-the-middle attacks.
Obfuscate code to prevent reverse engineering.
Protect mobile apps against tampering.
Implement root/jailbreak detection to prevent compromised devices from accessing the apps.
Implement mobile application code and runtime protection.
Implement RASP to counteract active attacks.
Ensure secure WebViews and IPC configurations.
Perform stringent deep-linking security checks.
Perform regular third-party SDK security assessments.
Engage in regular penetration testing and threat modeling.
Implement DevSecOps and secure SDLC approaches.
Use continuous monitoring based on Zero Trust principles.
Traditional Testing vs Continuous Mobile Application Protection
The shift toward modern security architectures highlights the limitations of periodic checks.
Capability | Traditional Security Testing | Continuous Runtime Protection |
Static code analysis | ✅ | — |
Vulnerability discovery | ✅ | ✅ |
Runtime attack detection | Limited | ✅ |
Tampering detection | Limited | ✅ |
Instrumentation detection | Limited | ✅ |
Root/Jailbreak detection | Sometimes | ✅ |
Real-time response | Limited | ✅ |
Continuous protection | ❌ | ✅ |
Post-deployment visibility | Limited | ✅ |
Key message: Traditional testing remains essential, but payment applications need an additional layer of runtime protection and continuous security monitoring.
Mobile Payment Application Security Checklist
Use this checklist to evaluate your mobile application protection platform:
Security Area | Status |
Secure Authentication | ✅ |
MFA | ✅ |
API Security | ✅ |
Data Encryption | ✅ |
Certificate Pinning | ✅ |
Code Obfuscation | ✅ |
Anti-Tampering | ✅ |
Root/Jailbreak Detection | ✅ |
Runtime Protection | ✅ |
RASP | ✅ |
Deep Link Security | ✅ |
IPC Security | ✅ |
WebView Security | ✅ |
Third-Party SDK Assessment | ✅ |
Penetration Testing | ✅ |
Business Logic Testing | ✅ |
Threat Monitoring | ✅ |
Secure SDLC | ✅ |
DevSecOps | ✅ |
Continuous Security Assessment | ✅ |
Why Protectt.ai for Payment App Security?
There are many vendors out there providing payment app security solutions but stop only at the testing stage, rendering you helpless once your app is installed on an unmonitored, possibly compromised end-user device. This is not the case with Protectt.ai; we go beyond a mere mobile app security testing tools checklist to offer real-time, live defense perimeters for your fintech applications.
With our full-scale mobile app security platform, we inject our native runtime protection straight into your UPI or payment application. With our embedded and application security features, security teams get real-time detection and prevention of activities such as reverse engineering, method hooking, malicious overlaying, and deep link manipulation. This, combined with our overall Mobile threat defense intelligence will ensure the resiliency, compliance, and security of your fintech app against zero-days and others as well.
We also prevent hackers from manipulating your business logic or injecting malicious code.
Our platform can immediately detect if an app is being run on jailbroken or rooted devices and instantly terminate risky sessions. You can continuously analyze behavioral deviations to catch zero-days, fraudulent patterns and automated bot activities before they can escalate. Our AI-led behavior monitoring is especially useful and we also offer exclusive features like AppBind which can enforce multi-parameter user and hardware verification checks to deal with social engineering attacks, credential theft, unauthorized, account takeovers and more.
We can also protect against man-in-the-middle attacks, SSL stripping, and data leaks during transit, and we use dynamic threat-aware encryption keys. ApiProtectt can safeguard back-end connections and prevent token hijacking, and JSON web token theft.
You can trust us to take care of your regulatory compliance because we are heavily optimized to work in high-risk sectors like financial services, banking, and insurance, government-to-citizen applications, and across other verticals.
Our tools can map directly to stringent security frameworks and standards and even accommodate out-of-the-box compliance compliance policy frameworks, especially regulations like the global PCI DSS standards, NPCI, SEBI, and RBI.
Be sure to talk to our experts to learn more.
Conclusion
Legacy mobile app security testing continues to be an important security measure to identify architecture or coding issues. However, security testing alone is not enough to cover all threats to UPI and payment applications. Payment applications run in hostile runtime environments where attackers use sophisticated techniques like instrumentation, reverse engineering, and overlay malware.
Static code analysis, dynamic testing, and penetration testing need to be supplemented by proactive runtime security protection. Security experts need to think about complicated attack surfaces like deep links, inter process communication, WebViews, API, SDKs, certificate pinning, business logic, and runtime attacks to provide comprehensive security. Runtime monitoring can be used as a complementary measure post-deployment to provide a comprehensive mobile application security platform capable of blocking fraud.
CISOs and security experts need to shift from routine security testing towards continuous mobile app security. For achieving true resiliency, companies need a full-fledged UPI security solution which includes application security protection, runtime threat detection, anti-tampering measures, code protection and continuous monitoring within the enterprise cybersecurity framework. Sign up for Protectt.ai today.
Frequently Asked Questions
Why is traditional mobile app security testing not enough?
Traditional testing focuses on identifying static code flaws before release. It cannot defend the app from dynamic runtime manipulation, instrumentation, or malware executed on compromised devices after deployment.
What is mobile app security testing for payment apps?
It is a specialized vulnerability management process that evaluates financial apps for risks like broken authorization, API vulnerabilities, and data leakage, ensuring UPI payment security and regulatory compliance.
How is UPI app security tested?
Testing involves SAST, DAST, mobile app penetration testing, and runtime security testing to uncover UPI app vulnerabilities such as deep link abuse, reverse engineering, and transaction manipulation.
What are the biggest security risks in payment applications?
The most critical payment application security risks include API abuse, certificate pinning bypass, code tampering, credential theft via malicious overlays, and sophisticated MITM attacks.
What vulnerabilities can mobile app penetration testing identify?
It can identify business logic flaws, weak cryptography, secure storage failures, IPC vulnerabilities, and authorization bypass techniques that automated mobile app security testing tools often miss.
Can static analysis detect runtime attacks?
No. Static analysis reviews code at rest. It cannot detect a live runtime attack detection scenario, such as an attacker actively hooking methods using Frida.
What is runtime protection in mobile applications?
It is a dynamic defense mechanism that monitors the app's execution environment. A fintech mobile security platform uses runtime protection to detect and block threats like debugging and repackaging in real time.
What is RASP in mobile app security?
RASP (Runtime Application Self-Protection) allows an app to detect and mitigate attacks natively. A mobile RASP solution automatically shuts down the app or blocks actions if tampering or instrumentation is detected.
Why is certificate pinning important for payment apps?
It hardcodes the expected server certificate into the app, preventing attackers from using fraudulent certificates to intercept sensitive transaction data via MITM attacks.
How can UPI apps prevent runtime attacks?
By integrating a mobile payment security platform that provides mobile application integrity protection, anti-hooking, and continuous threat detection aligned with Zero Trust principles.
How can payment applications prevent code tampering?
Through mobile app anti-tampering controls, checksum validations, code obfuscation, and application integrity monitoring to ensure the APK/IPA has not been maliciously modified.
Why are WebViews a security risk in mobile apps?
Improperly configured WebViews can execute malicious JavaScript, leading to cross-site scripting (XSS), token theft, and unauthorized access to native device features.
What are mobile application attack surfaces?
These include the network layer, local storage, inter-process communication (IPC), user interface (overlays), backend APIs, third-party SDKs, and the runtime environment itself.
How often should payment applications be security tested?
Testing must occur continuously. Organizations should integrate mobile app vulnerability assessment tools into their CI/CD pipelines (DevSecOps) and perform deep penetration testing before every major release.
Is penetration testing enough for mobile payment applications?
No. While penetration testing is a crucial mobile application security assessment, it is a point-in-time check. Apps require a continuous payment application security solution equipped with RASP to defend against post-deployment threats.
What is the difference between mobile app testing and runtime protection?
Testing identifies vulnerabilities in the code during development, whereas runtime protection actively blocks exploits and malware while the user operates the app.
How can fintech companies secure mobile applications?
Fintechs must adopt a holistic application security lifecycle. This includes implementing Mobile threat defense, utilizing a mobile application security solution, enforcing secure coding, and establishing continuous runtime attack detection.