9 Account Takeover Attacks That Weaponise Customer Trust Against Payment Platforms

Types of account takeover attacks that your payment operations team must understand and prevent

Imagine one of your most reliable customers—a seller with a spotless payment record—suddenly rerouting payouts to an unknown bank. Nothing in your dashboards looks abnormal because the login, device and IP all match the user’s history.

That is an account takeover (ATO) attack silently hijacking that trusted relationship, converting years of transaction data into an instant disguise for fraud, refunds and chargebacks.

This threat is accelerating rapidly. ATO incidents jumped 24% year over year in 2024, siphoning hard-earned revenue from businesses worldwide. Every pound lost is compounded by reputational damage and the regulatory scrutiny that accompanies compromised customer identities.

Protecting your platform now requires layered defences that go far beyond password policies. Here are nine ways attackers stage account takeover attacks to abuse credentials, devices, support teams and APIs—and what practical steps you can take to shut each path down.

Account Takeover Attack #1: Credential Stuffing Through Automated Bot Networks

Credential stuffing turns leaked usernames and passwords from past breaches into direct threats against your payment accounts. Attackers feed those credentials into automated software that hammers your login API at machine speed, hoping reused passwords still work.

In minutes, hundreds of thousands of attempts can hit your platform. Each request routes through rotating proxies and uses CAPTCHA-bypass plugins that mimic human browsing behaviour.

Simple IP blocking rarely helps because bots spread across global IP ranges. Instead, watch for patterns humans don’t create: login bursts against multiple accounts from one device fingerprint, impossible travel sequences or identical session timings.

Multi-factor authentication remains your strongest defence. A one-time code or hardware key breaks the attack’s reliance on static passwords. Couple this with adaptive rate limiting that throttles requests when traffic resembles automation. This denies bots the scale they need to succeed.

When a stuffing wave breaches your defences, suspend the affected account immediately. Force a password reset and monitor outgoing payments closely. For platforms that settle funds instantly, every minute counts.

Unchecked, a single compromised account can trigger chargebacks, refunds and reputational damage before you even spot the traffic spike.

Account Takeover Attack #2: SIM Swap Attacks Targeting Payment Authentication

SIM swapping is a technique that shifts your customer’s phone number to a SIM the attacker controls, instantly rerouting every SMS-based security code to fraudsters.

Criminals present stolen personal details to mobile network support and convince carriers to port the number. Once the switch completes, attackers reset passwords, intercept transaction confirmations and drain balances before customers notice their unexplained service disruption.

Payment platforms face serious exposure here. SMS one-time passwords remain widespread, yet a successful port makes that second factor worthless. Your fraud teams typically spot compromises when logins originate from new devices minutes after a mobile number change, followed by rapid high-value transfers.

Reducing exposure starts with stronger authentication factors. App-based authenticators, FIDO tokens or biometric prompts deny attackers the text channel they depend on. Set up real-time alerts for any request to change a user’s phone number and require step-up authentication before approving modifications.

When a swap slips through, speed matters. Lock the account immediately, reroute verification to a channel not tied to the compromised phone number and review all transactions since the SIM change.
Reversing fraudulent payments within settlement windows limits direct losses while you investigate the breach’s root cause.

Account Takeover Attack #3: Session Hijacking in Public Payment Environments

Beyond exploiting weak passwords or phone vulnerabilities, attackers can hijack active sessions to bypass authentication entirely. They position themselves between your customers and your platform—typically through open café hotspots or rogue WiFi access points—then capture session cookies to access authenticated accounts.

Public networks amplify this risk because payment apps keep users signed in, store multiple cards and promote one-tap checkout. Intercepted cookies instantly expose stored payment methods. Fraudsters can add beneficiaries or purchase high-value items before detection systems trigger.

You can identify hijacks through session anomalies: mid-checkout IP address changes, concurrent device activity mirroring active carts or impossible geographic jumps within seconds. Combining these signals with velocity checks provides your monitoring systems with the context needed to flag takeover attempts.

Implement end-to-end TLS on every request and enforce tight session expiry windows, binding tokens to the originating devices and mandate re-authentication for card-on-file modifications. These measures deny attackers the time needed to exploit stolen cookies.

When you suspect a breach, immediately terminate sessions, place accounts under review and initiate payment-method verification sweeps. Mobile traffic requires particular attention, as customers frequently pay while mobile and connect through any available network.

Account Takeover Attack #4: Phishing Campaigns Targeting Payment Platform Users

While technical attacks exploit system vulnerabilities, phishing remains a favoured gateway because it preys on trust instead of code. Attackers craft emails, texts or voice calls that mimic your platform’s brand. They lure customers to bogus sign-in pages or fake support chats.

These messages often reference recent payments or ‘urgent’ security checks to spark immediate action.

Sophisticated campaigns now personalise the bait. A fraudster may spoof a merchant’s domain and send a convincing “payment method declined” notice. This routes the victim to a cloned checkout.

Once the customer re-enters card details, login credentials and any one-time codes, the attacker gains full access to the genuine account. Your usual velocity or geolocation checks become irrelevant.

You can spot these attacks by combining technical controls with human vigilance. DMARC, SPF and DKIM settings reduce brand spoofing. Link-scanning tools can also help you flag look-alike domains. Customer reports frequently surface campaigns that slip past automated gateways, so encourage users to forward suspect messages to your abuse mailbox.

Prevention requires layered defences across multiple touchpoints. Built-in browser warnings make phishing attempts more obvious. In-app security banners educate users in real-time. Regular customer education reinforces these messages.

For high-risk actions such as adding a new payee, deploy phishing-resistant authentication like app-based prompts or hardware tokens instead of SMS codes.

When a phish succeeds, speed determines the outcome. Reset credentials immediately, revoke active sessions, verify stored payment methods and review recent transactions. A prompt, transparent response limits financial loss and reinforces customer trust, turning a potential crisis into a manageable incident.

Account Takeover Attack #5: Malware-Based Payment Information Harvesting

The most insidious attacks don’t require customer mistakes—they operate invisibly through malicious software. Payment-focused malware is purpose-built code installed on your customers’ devices to steal login credentials, session cookies or payment data.

This gives attackers direct access to your checkout and wallet flows. Keyloggers record every keystroke, information stealers lift card numbers from autofill fields and browser injections quietly rewrite payment forms so credentials flow directly to the attacker’s server.

Mobile banking trojans overlay fake screens on legitimate apps to intercept one-time passwords and authorise fraudulent transfers. Once embedded, the malware hunts for stored payment instruments and authentication tokens, then transmits the stolen data back to attackers.

Criminals often bundle the compromised accounts with other stolen data and sell everything on dark-web markets, expanding the damage far beyond the initial device. Automated distribution kits mean a single campaign can reach thousands of devices in days.

Spotting an infected user hinges on behavioural signals. Watch for sudden changes in device fingerprint, impossible-travel logins or a burst of high-risk transactions from a previously low-value account.

Your defences start at the endpoint. Up-to-date anti-malware, mandatory HTTPS and content-security policies deprive most payloads of a foothold. Inside your platform, run real-time application monitoring to flag altered payment pages and block suspicious script calls.

When you confirm a compromise, freeze stored payment methods, force device re-verification and roll back unauthorised transactions.

Malware-as-a-service continues to mature, so your response playbook must evolve just as quickly, combining threat intelligence with ongoing user education to stop tomorrow’s variants before they reach your production environment.

Account Takeover Attack #6: Social Engineering Against Customer Service Teams

Even the most sophisticated technical defences can crumble when attackers target the human element. With MFA, device checks and velocity limits blocking direct login abuse, fraudsters pivot toward your support desk.

Social engineering in payment operations means coaxing service agents into granting account access or changing payment details by impersonating legitimate customers. These calls sound authentic because fraudsters reference real data from previous breaches, bypassing your technical controls entirely.

A typical attack starts with urgency: “My payment failed and I’m boarding a flight in ten minutes.” The caller sprinkles in partial card numbers, recent transaction amounts or bank account details.

This builds credibility before applying pressure tactics. “Please just reset the password—I can’t miss this payment.” Such urgency pushes agents to skip verification steps.

You can spot these attacks through inconsistent verification answers, callback number changes or customers suddenly rejecting multi-factor prompts. Your defence centres on people, not just systems.

Train every agent to follow strict verification scripts even when callers seem irate. Require mandatory supervisor approval for high-risk changes. Institute out-of-band callbacks to registered numbers before altering payout settings.

When breaches occur, freeze outgoing payments immediately and launch transaction reviews. Call the legitimate customer to confirm recent activity. Your technical controls matter but disciplined human processes keep fraudsters two steps behind your operation.

Account Takeover Attack #7: Device Takeover Through Malicious Mobile Applications

The shift to mobile payments has created new attack vectors that complement traditional malware tactics. Mobile device takeover occurs when malicious apps infiltrate your customers’ phones and gain access to legitimate payment software.

Mobile banking fraudsters excel at this attack, silently capturing credentials and session tokens that grant attackers the same account privileges your app provides.

Attackers reach your users through three primary channels. Some publish convincing fake payment applications that mimic your interface. Others compromise legitimate apps by injecting malicious SDKs into trusted software.

The most advanced overlay attacks display counterfeit screens over your checkout process, capturing card details and authentication codes as customers enter them.

You can identify compromised devices by monitoring for unusual customer behaviour. For example, a London-based customer suddenly authorising multiple transfers from a new Android device raises red flags. Apps requesting dangerous permissions just before large purchases signal potential takeover.

Prevention begins before your customers download anything. Distribute apps only through verified app stores. Inspect every third-party library your development team integrates. Monitor for unusual permission changes during app runtime.

When you suspect a takeover, immediately freeze in-app payments. Ask the customer to re-authenticate on a clean device. Route high-value transactions through separate verification channels. Mobile payments continue expanding, making these protective measures vital for your revenue and customer trust.

Account Takeover Attack #8: Business Email Compromise Affecting Payment Operations

While consumer-facing attacks grab headlines, business email compromise (BEC) represents one of the most costly vectors for payment fraud. This approach happens when attackers seize control of a legitimate corporate inbox. They use that trust to redirect money their way.

In payment operations, fraudsters don’t need malware or brute-force tools. An authentic-looking request, accompanied by a company signature, often does the job.

Once inside your mailbox, criminals study past conversations. Then they launch targeted attacks: swapping bank details on supplier invoices, instructing your finance team to “update” payout information or impersonating executives who “need urgent international transfers.”

Marketplace platforms face heightened risk because they handle thousands of vendor payments. A single falsified email can alter payout instructions at scale.

You can spot many BEC attempts through subtle anomalies. Look for messages that break normal writing patterns. Watch for logins from unfamiliar IP addresses. Flag sudden changes to payment instructions outside your agreed workflow.

Email security that scans for spoofing, plus behavioural analytics that identify unusual login locations, provides your first line of defence.

Protection can’t rely on single-person verification. Multi-party payment approvals make attacks harder to execute. Out-of-band callbacks to confirm banking changes add another barrier. Vetted vendor records prevent unauthorised modifications from succeeding.

If a breach occurs, freeze your affected payout queue immediately. Verify every altered account. Review recent transactions for tampering before any funds leave your system.

Account Takeover Attack #9: API Exploitation in Payment System Integration

Another sophisticated attack lies in your technical infrastructure itself. Every new API endpoint you publish attracts attention from fraud teams and attackers. API exploitation happens when adversaries probe endpoints for weaknesses—missing authentication, poorly validated parameters or weak rate limits.

They exploit these gaps to impersonate legitimate requests and access your payment infrastructure.

Attackers use many techniques. They bypass or forge authentication tokens to impersonate merchants and extract complete account data. They also abuse lenient rate limits to brute-force tokens or scrape card details at scale, hiding behind rotating IP addresses.

The damage is immediate once they’re inside. Stolen payment methods, manipulated payout instructions and access to every wallet attached to an account. API calls often sit behind your web or mobile interface, so these breaches can progress undetected until reconciliation reveals unexpected balances.

Watch for unusual request patterns to spot trouble early. Spikes in POST traffic, calls from unrecognised IP ranges or authentication anomalies like expired tokens suddenly working again surface these deviations in real time.

Prevention requires strong, layered authentication. Use mTLS or signed JWTs tied to specific roles, combined with strict parameter validation and hard rate caps. Encrypt secrets, rotate keys automatically and isolate high-risk actions behind step-up controls.

When an exploit occurs, act fast. Revoke affected keys, suspend automated payouts pending review and run integrity checks across recent transactions. Quick action limits downstream fraud and protects the confidence your partners place in every API call.