APIs used to be the quiet backstage crew that made apps feel magical. Now attackers have learned the script — they walk onstage, deliver perfectly polite lines, and walk off with the props. In H1 2025 Imperva observed 40,000+ API incidents across 4,000+ monitored environments, including an application-layer DDoS that spiked at 15 million requests per second against a financial API.
The scariest part? Most of these aren’t noisy probes — they’re perfectly valid requests that bend business logic: promo-loops that drain discounts, gift-card cracking campaigns, targeted data scraping, and stealthy account takeovers. These attacks hide inside the very flows your product uses to serve customers, so signature-only tools and blunt rate limits shrug them off while the damage mounts.
That’s why this report matters. It’s not just telemetry — it’s a playbook: how to find forgotten or shadow endpoints, how to validate actions at runtime (not just the shape of a request), how to enforce per-object authorization, and how to tie bot defenses to business KPIs (promo redemptions, refund spikes, reservation velocity) so you stop attacks that look “normal” but are anything but.
Read on for the trends, real-world case studies, and a practical, prioritized checklist you can use this week to reduce risk — and if you want the full data and remediation templates, download the Imperva API Threat Report.
How attackers changed the game — a plain explanation
APIs do the real work of modern apps: they check balances, apply discounts, move money, and return user profiles. Attackers realized that sending valid-looking API calls that abuse those workflows gets them money, data, or inventory — and often without tripping classic security alarms.
Three things made this shift possible:
- Scale + stealth: Cheap automation and proxy networks let attackers run millions of “normal” requests at scale while staying below volume alarms.
- Business-logic abuse: Bots follow the exact API contract (so WAFs and signature rules see nothing suspicious) but exploit semantic gaps — e.g., allowing a promo to be applied repeatedly.
- Operational blind spots: Hidden or misconfigured partner APIs (shadow endpoints) and inconsistent token validation leave doors wide open.
The result: attackers focus where value is — data-access (~37%), checkout/payment (~32%), and authentication (~16%) — and extract outsized impact with minimal noise.
The five biggest truths from the report (what every exec should know)
- APIs are the primary attack surface now. Attackers prioritize endpoints that map to revenue or identity. Protect those first.
- Valid ≠ safe. The most damaging attacks are valid requests that break business logic; they require context, not signatures.
- Discovery is non-negotiable. Organizations routinely have 10–20% more live endpoints than they believe. Shadow APIs are a top source of compromise.
- Automated, targeted scraping and promo-loop attacks bleed revenue quietly. Read operations are not harmless — enforce object-level rules.
- Combine defenses — signatures alone won’t cut it. Runtime schema enforcement, behavior analytics, adaptive throttling and short-lived tokens are core capabilities.
Real attacker playbook: how they get in and what they do
- Recon & discovery: Scan for undocumented endpoints; probe partner integrations.
- Tooling: Headless browsers (Puppeteer, Selenium), proxy/botnet pools, Postman/Burp scripts; bots emulate human timing and browser characteristics.
- Execution: Parameter tampering, promo-looping, gift-card cycling, credential stuffing followed by token replay.
- Objective: Data exfiltration, immediate revenue theft, account takeover, or preparation for larger intrusions.
A simple, prioritized defensive playbook (what to do tomorrow)
For executives — 30,000-foot actions
- Mandate continuous API discovery and classify APIs by business impact (money, PII, critical workflows).
- Assign API ownership (product + security) and report a small set of API KPIs to the board (e.g., % APIs discovered vs documented, % high-risk APIs protected).
For practitioners — tactical controls
- Discovery & inventory: Combine passive and active discovery; close or secure shadow APIs.
- Schema & contract enforcement: Enforce OpenAPI/GraphQL contracts at runtime; reject unexpected fields.
- Object-level authorization: Don’t treat all reads equally — apply per-object permissions and field filtering.
- Behavioral detection tied to business KPIs: Monitor promo redemptions, refund spikes, reservation rates and trigger actions when anomalies appear.
- Adaptive rate limits & bot management: Use context-aware throttling (risk-based) rather than coarse global limits.
- Short-lived, scoped tokens + step-up MFA: Reduce token replay and ATO effectiveness.
- Supply-chain hygiene & patching: Prioritize Log4j/WebLogic/Joomla exposures and vet third-party API scopes.
Quick wins that show ROI in weeks
- Run automated discovery and block a high-risk shadow endpoint — you’ll often cut a real attack vector the same day.
- Enforce object-level authorization and runtime business-rule validation — stop parameter tampering, promo-looping, and targeted data scraping by validating who can access which object and under what conditions, in real time.
- Apply adaptive throttling on high-value endpoints during promotions — preserves UX for real customers while blocking scalpers and automated abuse.
What success looks like (metrics to track)
- % of APIs discovered vs. documented
- Number of shadow endpoints closed per quarter
- Reduction in promo-abuse incidents (count & $ value)
- Time to revoke compromised tokens after detection
- % of high-risk endpoints protected with runtime enforcement
Closing narrative — what you should take away
APIs are not just another web surface — they are the business. Attackers have adapted: they automate, emulate humans, and abuse valid business flows. The defensive answer is not louder firewalls; it’s smarter, business-aware security: discover everything, understand every endpoint’s business impact, and enforce contracts and object-level rules at runtime while using behavior-driven bot defenses to protect the workflows that matter.
If you treat API security as a technical checkbox, you’ll miss the attacks that matter. If you treat it as a business problem and apply the defensive playbook above, you turn APIs from an exposure into a controlled gateway.
Want the full data, charts, and playbook?
Download the complete Imperva API Threat Report to see the telemetry, industry breakdowns, and detailed remediation steps.
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