TL;DR
- Travel website accounts are prime ATO targets as they hold stored payment information and loyalty point programs that are less secure than primary account flows. The LSA reported that $3.1 billion in redeemed loyalty points are fraudulent annually.
- ATO fraud is costly. Chargebacks can be $2,000+ for travel companies. Companies like Booking[.]com have repeatedly faced ATO attacks between 2020 and 2025.
- Prevention best practices include risk-based MFA (with rules taking into account international travel as normal), hardening loyalty account recovery flows instead of login alone, and using fingerprinting signals to catch ATO attempts early.
- Most travel companies combine three tool types: MFA and identity verification (Duo, Ping Identity), device fingerprinting and bot detection (cside, HUMAN Security), and anti-fraud suites (Sift, Forter).
What is account takeover fraud in travel websites?
Account takeover fraud happens when an attacker gains access to a real customer's account and uses it for fraud or abuse. In travel, this typically starts with one of a few entry points:
- Credential stuffing with reused passwords, phishing disguised as official travel company communications, or weak password recovery flows.
In most verticals, ATO leads to payment fraud. In travel, it also includes loyalty fraud. Attackers drain frequent flyer miles or transfer hotel points to burner accounts.
This is not a niche issue either. EY’s report states that the global value of loyalty points is over $200 billion. ATO related fraud can take roughly 150-180 days to investigate.
Why travel website accounts are targeted in ATO
For an attacker, a compromised travel account is one of the highest-payoff targets online. Here's what they get access to in a single breach:
- Loyalty currencies, stored payment methods enabled for high ticket purchases, and rich personal data like passport numbers.
User behavior doesn't help either. Most reuse passwords across platforms, and few treat their hotel or airline login with the same caution they'd give a bank account. Many users only create an account in a hurry at the end of a booking session when prompted by the platform. fast checkout, saved payment methods, and persistent sessions all widen the attack surface.
This is why attackers target travel websites (airlines, hotel chains like Hilton and Marriott, and booking platforms like Expedia and Booking [.] com).
Best practices for travel & hospitality websites to stop account takeover fraud
1. Require MFA at the right moments
- Trigger step-up verification for unusual logins: New device, unfamiliar IP, different country. Keep in mind that for travel websites, customers legitimately log in from different countries. Flag the combination of signals, not any single one.
- Risk based MFA works better than blanket rules.
2. Protect account reset flows
- Rate-limit account reset requests: A burst of resets targeting multiple accounts signals credential stuffing.
- Don't rely on email-only recovery: If the inbox is compromised, the account is gone. Add device verification or a secondary contact method.
Loyalty program accounts often have weaker recovery flows than the main booking account. Different team, different system, same (or higher) value. These need the same protection.
3. Use risk based signals to catch ATO
- Device and browser signals: Fingerprinting, browser config, and elements like screen resolution establish a per-user baseline.
- Network signals: VPN usage, proxy detection, IP reputation, geolocation mismatches.
- Behavioral patterns: A session that logs in and immediately navigates to loyalty transfers behaves very differently than someone browsing destinations.
- Common red flags: Impossible travel patterns, multiple accounts from one device, new device login followed by instant account changes.
4. Catch automated ATO attempts early
Stealth browsers and AI-bots mimic real user behavior well enough to bypass CAPTCHAs and basic bot detection (stealth browser usage grew 11x in 2025). More advanced measures are needed to catch credential stuffing and automated login testing early:
- IP-based rate limiting alone isn't enough: Residential proxies make automated traffic look legitimate.
- Specialized detection: Browser fingerprinting catches browser mismatches, device inconsistencies, and behavioral insights that indicate AI-driven ATO activity.
5. Create response plans for ATO attacks
- Challenge: Present step-up auth to give the real account holder a path back in.
- Notify: Alert the customer of potential account tampering.
- Lock: Freeze loyalty transfers, booking changes, and payment method updates on flagged accounts.
- Investigate: Review what changed. New email, transferred points, new bookings, or modified traveler profiles.
Multiple loyalty point transfers specifically should have a secondary verification. Similar to how banks handle wire transfers.
6. Tune fraud thresholds based on historical patterns
Winter travel, summer peaks, and spring break affect what "normal" login behavior looks like. More cross-border logins, more new devices, higher booking volumes.
- Review prior seasonal login patterns before each peak window
- Adjust detection rules and thresholds ahead of high-volume periods
- Retune after each spike based on what actually happened — not what you predicted
Also account for major events that create regional spikes (Olympics, World Cup, large festivals).
7. Make sure your website isn't leaking user credentials
Code injections are one of the most overlooked ATO vectors. Attackers can inject malicious scripts directly into your site that hijack login forms or booking pages to steal credentials while everything looks normal to your server/API security tools.
The FTC notes that 416,582 cases of identity theft in the U.S. were facilitated by digital skimming in a single year.
- Monitor all third-party and first-party scripts continuously. Third-party tags, analytics snippets, ad pixels, and web widgets all introduce code you don't fully control. Any of them can be compromised and turned into a credential exfiltration point.
- Use a web security platform like cside to automate client-side script monitoring. cside Client-side Security watches for data exfiltration attempts and code injections targeting login pages, booking flows, and loyalty point pages.
Best account takeover prevention tools for travel websites
Covering ATO end-to-end usually takes more than one tool. Most travel companies build their stack across three categories.
- MFA / identity verification: Adds a second layer beyond passwords. One-time codes via email or SMS or authenticator apps are a first line of defense. Auth0 and Duo are commonly used.
- Fingerprinting / bot detection: Tracks device, browser, and behavioral signals to identify credential stuffing and automated login abuse. Also provides raw signals your fraud rules to identify suspicious sessions that indicate ATO. cside and HUMAN Security are strong fits for travel. Travel sites already deal with heavy bot traffic from fare scrapers and inventory checkers, so bot detection handles multiple problems at once.
- Anti-fraud suites: Score risk across login, booking, and post-transaction activity in one platform. These are typically enterprise focused platforms that aim to solve fraud vectors end to end, but offer less flexibility. Sift and Forter are well-established for travel companies.
Real world examples of ATO attacks on travel websites
In April 2026, Booking[.]com confirmed that attackers had been accessing customer reservation data through compromised hotel partner accounts. Attackers sent hotel partner staff emails impersonating Booking[.]com to trick employees into executing malware. They then contacted customers directly, posing as the hotel, demanding additional payment or card verification using real booking details to appear legitimate.
A more typical ATO in travel looks like this: A customer reuses a password on an airline loyalty account. That credential pair shows up in a breach dump. An attacker runs automated login attempts during a holiday travel spike. One login works. By morning, the account email has been changed, 85,000 miles transferred to a burner account, and a business class ticket booked on the stored card. The customer discovers it when their points balance reads zero.
Why account takeover matters for travel websites
ATO isn't just a security problem. It hits revenue, operations, brand trust, and compliance simultaneously:
- Fraud losses: Attackers drain loyalty balances (miles, points, companion certificates, upgrade credits), book travel on stored cards, and resell reservations. The Loyalty Security Association reported that $3.1 billion in redeemed loyalty points are fraudulent annually leading to ~$1 billion in direct losses.
- Chargebacks and disputes. Travel transactions are high-ticket. A single fraudulent booking can generate a $2,000+ chargeback, and airlines and OTAs eat those costs because it's genuine fraud on a real account.
- Customer trust and retention: In the US, 83% of consumers claim they will reduce spending with a business in the aftermath of a breach.
- Support and ops burden: Wave of password resets, account recovery requests, manual booking reviews, and rebooking for affected customers
- Compliance and regulatory exposure: PCI DSS for stored payment data and GDPR for EU travelers' personal information.
- Cyber insurance implications: Insurers increasingly evaluate MFA adoption, access controls, and fraud prevention posture during underwriting.
The role of fingerprinting in account takeover detection
Once an attacker has valid credentials, passwords are useless as a defense. If they can intercept a one-time code, MFA fails too. Browser fingerprinting adds a detection layer underneath both that is harder to evade.
- ATO signal collection: Browser fingerprint, hardware identifiers, screen properties, and network metadata all form a baseline for each visitor. When parts of that baseline don't match (mismatched timezone, signs of a headless browser) it alerts of a suspicious session.
- Detect automated ATO attempts early: One device cycling through dozens of user-password combos. A browser presenting as Chrome on macOS but running in a headless Linux environment. Login requests at inhuman speed from rotating proxies. Fingerprinting catches credential stuffing bots that slip past CAPTCHAs and rate limiters.
Why cside is the best fingerprinting option for travel website companies
cside combines browser fingerprinting with JavaScript integrity monitoring, giving travel companies both ATO detection and web skimming detection in one platform.
- Malicious AI bot detection: Detects headless browsers that mimic real user behavior to bypass traditional bot defenses and run credential stuffing at scale.
- Protects the pages attackers target most: Secures booking pages, loyalty account portals, and payment flows against skimming, data exfiltration, and session hijacking. cside is a leading solution for PCI DSS 4.0.1 script monitoring.
- Third-party script monitoring: Watches every script running on your site (third-party code, accessibility tools, booking widgets, analytics tools, ad pixels, affiliate tags) and flags when any of them start exfiltrating credentials or payment data.
- Developer-first integration: Raw fingerprint signals via API for custom fraud rules, plus curated signal groupings ready out of the box.
To get started with cside, sign up or book a demo.
