Why UPI and Digital Payment Platforms Need Continuous Security Audits

UPI crossed 16 billion transactions in a single month earlier this year. That number alone should tell you why fraudsters treat payment platforms as their most attractive target, not banks’ back-office systems, not enterprise ERPs, but the apps sitting on 400 million phones processing money in real time. At Speqto Technologies, we’ve spent the last few years auditing payment infrastructure for fintechs and NBFCs, and one pattern keeps repeating: teams treat security audits as a one-time compliance checkbox instead of an ongoing discipline. That mindset is exactly what gets exploited.

A one-time audit is already outdated by the time it’s signed off

We worked with a mid-sized lending platform that had cleared a VAPT (Vulnerability Assessment and Penetration Testing) audit in Q1. By Q3, they had shipped four new API endpoints for a partner bank integration, added a new UPI AutoPay feature, and updated their SDK version. None of that went through security review because, technically, “the audit was done.” We found a broken object-level authorization issue in one of those new APIs that would have let an authenticated user pull transaction details of a different customer by simply changing an ID in the request. That’s not a hypothetical – it’s a class of bug (BOLA/IDOR) that shows up in almost every payment API we test, and it only gets caught if testing happens with every release, not once a year.

UPI’s own architecture creates recurring attack surfaces

UPI isn’t a single app, it’s an ecosystem of PSPs, TPAPs (third-party app providers like the apps your customers actually use), NPCI’s switch, and the issuing/acquiring banks. Every layer is a potential entry point:

• Deep link and intent manipulation — malicious apps registering the same UPI intent filters to intercept payment requests on Android devices.
• QR code spoofing — static QR codes that get physically or digitally tampered with to redirect payments, something we still see in offline merchant audits.
• Session and token handling — VPA linking flows and device binding tokens that don’t expire or rotate properly, letting a compromised device retain access longer than it should.
• Screen-sharing and remote access scams — not a code vulnerability per se, but platforms that don’t detect anomalous session patterns (screen mirroring apps, accessibility service abuse) end up facilitating fraud that gets blamed on “user error” when better runtime monitoring could have flagged it.

None of these are theoretical. RBI’s own annual reports on digital payment frauds have repeatedly flagged social engineering combined with technical loopholes as the dominant fraud pattern, not brute-force hacking.

Regulatory pressure is real, but it’s not the whole reason

RBI’s cybersecurity framework for banks, the NPCI’s periodic circulars, and PCI-DSS requirements for anyone handling card data all mandate periodic audits. If you’re a PA/PG under RBI’s authorization framework, you already know the paperwork. But compliance-driven audits tend to be scoped narrowly – checklist-based, focused on what auditors are asked to look for. We’ve seen platforms pass their annual PCI-DSS audit with a clean report and still have an exposed staging environment reachable from the public internet with production database credentials hardcoded in a config file. Compliance tells you what’s required. It doesn’t tell you what’s actually exploitable.

What continuous actually means in practice

For the payment platforms we work with, we push for a layered cadence instead of a single annual event:

• Pre-release security review for every feature touching money movement, authentication, or PII – not just major releases.
• Quarterly VAPT covering APIs, mobile apps (both Android and iOS separately, since their attack surfaces differ), and infrastructure.
• Red team exercises twice a year that simulate actual fraud scenarios – account takeover chains, not just individual CVEs.
• Continuous dependency and SDK monitoring, because a huge chunk of payment app breaches start with a vulnerable third-party library nobody remembered to update.
• A live bug bounty or responsible disclosure program once the platform has matured past MVP stage – external researchers routinely catch what internal teams miss simply because they’re not blind to their own assumptions.

The cost conversation founders always raise

Every CTO we talk to eventually asks whether continuous audits are worth the recurring spend versus a bigger annual engagement. Here’s the honest answer: a single fraud incident involving customer funds doesn’t just cost the refund amount. It costs NPCI/bank relationship trust, it triggers RBI scrutiny that can slow down your next product approval, and it shows up in app store reviews within hours. We’ve seen a client’s customer support tickets spike 40% in a week after a single viral fraud complaint on social media, most of it unrelated actual users panicking about their own accounts. Continuous audits are cheaper than that recovery, every time.

Where to start if you haven’t done this yet

If your platform has never had a dedicated payment-focused security audit (as opposed to a generic web app pentest), start there. Get a clear picture of your API attack surface, your mobile app’s binary security, and your session management logic. Then build the cadence around your release cycle, not the calendar year. Payment security isn’t a project with an end date – it’s closer to maintenance on a moving vehicle. You don’t service it once and park it.