MOVE MONEY
STAY SECURE.
In fintech the vulnerability and the loss are the same transaction. We test payment logic, identity flows, and the cardholder data environment the way an adversary who wants the balance would.
THE FINTECH THREAT MODEL
The attacker is paid in the same currency you are
Most sectors lose data. Fintech loses money in the same request the flaw is triggered. That changes attacker economics: a rounding error in refund handling, a race between authorisation and capture, or a negative-quantity transfer is worth exploiting at scale immediately, not sold on later.
Fraud operators, not just intruders
The persistent adversary is a fraud ring with stolen identity data, disposable accounts, and automation. They probe onboarding, KYC document handling, stored-value transfers, and payout rails looking for logic that trusts client-supplied state. They rarely need a memory-corruption bug.
Third parties hold the keys
Sponsor banks, card processors, KYC vendors, ledger providers, and CRM tooling all sit inside the transaction path. Compromise of a vendor with API access to customer records produces the same outcome as compromise of your own platform, with less warning.
WHAT DRIVES THE REQUIREMENT
For a payments or lending business, testing is rarely optional. Regulators, acquirers and the customers who move money all assume the platform has been adversarially tested.
PCI DSS 4.0
Requirement 11.4 mandates internal and external penetration testing of the cardholder data environment and of segmentation controls, with defined methodology and retesting of remediated findings.
PSD2 / SCA
Strong customer authentication and dynamic linking obligations create testable properties: exemption abuse, step-up bypass, and 3DS flow manipulation.
Sponsor bank and scheme oversight
Bank and card scheme partners commonly require independent testing evidence before or during onboarding, and again on material platform change.
SEC / disclosure regimes
Material incident disclosure timelines make detection and evidence quality a reporting problem, not only a security one.
WHAT WE TEST
Payment & transaction logic
- Authorisation, capture, refund, and reversal sequencing abuse
- Race conditions on balance, transfer, and payout endpoints
- Tokenisation and vault boundary testing
- 3DS and SCA exemption handling
- Ledger invariant testing: can a sequence of valid calls create value?
Identity, onboarding & account access
- KYC document and liveness workflow manipulation
- OAuth 2.0 and OpenID Connect flow validation
- Account takeover chains through recovery and support paths
- Step-up authentication bypass on high-value actions
- Multi-tenant and role boundary enforcement
Platform & cardholder data environment
- REST, GraphQL, and WebSocket authorisation testing
- CDE segmentation validation across AWS and Azure, with GCP scoped case by case
- CI/CD pipeline and secrets management review
- Partner and webhook integration abuse, including SSRF
- Logging and alerting coverage for financial-impact events
HOW WE WORK
The testing runs in parallel against transaction logic, authentication and infrastructure. A reachable state only becomes a finding once it is exploited, and what counts as a defect is the human call.
Money-flow mapping
Trace every path value can take through the platform: ledgers, payment rails, partner APIs, and manual operations tooling. Scope follows the money, not the asset inventory.
Threat modelling
Adversary profiles built for the specific vertical (neobank, acquiring, lending or custody) and for the fraud patterns that vertical attracts.
Agentic exploitation
Agent swarms work transaction logic, authentication and infrastructure in parallel, chaining low-severity findings into demonstrated financial impact. Whether a reachable state is a defect or intended ledger behaviour is a judgement about your books, and it stays human.
Evidence and control mapping
Reproducible findings mapped to PCI DSS and the requirements your sponsor bank or auditor applies, with remediation guidance written for engineers.
WHAT YOU RECEIVE
WHEN FINTECH BREAKS
Public disclosures worth reading closely. Note how few involve a novel exploit, and how many involve internal tooling and people with legitimate access.
Cash App (Block)
2022A departed insider retained access to internal reports containing customer brokerage data.
8.2M customers notified via SEC 8-K filing.
Revolut
2022Social engineering against staff led to internal portal access and data exfiltration.
Customer data exposed, followed by targeted phishing against those customers.
Robinhood
2021A support engineer was phished by phone, granting access to customer support tooling.
Millions of customer records exposed through legitimate internal tooling.
BlockFi (via HubSpot)
2022A CRM vendor breach exposed client names, emails, and phone numbers.
Enabled downstream credential-stuffing and SIM-swap attempts against wallets.
FREQUENTLY ASKED
Do you test in production or in a staging environment?+
Both, depending on risk tolerance and regulatory constraints. Transaction logic often only behaves realistically in an environment wired to real rails, so testing windows and non-settling instruments are agreed in advance.
How do you handle cardholder data during testing?+
We do not store, process, or transmit real cardholder data. Testing uses synthetic data, scheme test cards, and processor sandbox credentials. Where a finding requires demonstrating access to real records, we capture the minimum evidence needed and mask it.
Can this satisfy PCI DSS requirement 11.4?+
The engagement is structured to produce what an assessor looks for: defined scope covering the cardholder data environment and its segmentation, a documented methodology, exploitation evidence, and retest results. Your QSA determines sufficiency for your specific assessment.
What do you find in fintech platforms that scanners do not?+
Logic. Refund and reversal sequencing, currency and rounding handling, race conditions on transfers, exemption abuse in authentication step-up, and authorisation gaps between services. None of these are pattern-matchable; they require reasoning about what the system is supposed to guarantee.
Find out what a sequence of valid requests can do to your ledger
Tell us which rails you run on and where value can move. We will scope the engagement against that, not against a template.