Credential Stuffing

What is Credential Stuffing?

Credential Stuffing is an automated attack where threat actors use stolen username and password combinations to try logging into multiple websites. By exploiting reused credentials across services, attackers attempt to gain unauthorized access to user accounts at scale.

How does Credential Stuffing work?

Attackers typically obtain credentials from previous data breaches, phishing campaigns, or underground marketplaces. These credentials are then tested in bulk using bots or scripts that mimic legitimate login behavior.

To avoid detection, attackers may space out attempts, rotate IP addresses, or simulate user behavior. Even a small match rate can provide access to valuable accounts for financial fraud, identity theft, or further credential-based attacks.

Memcyco’s Solution for Credential Stuffing

Traditional solutions rely on server-side thresholds, velocity checks, or behavioral analytics to flag credential stuffing after the fact. Memcyco intercepts these attacks in session, detecting the use of stolen credentials in real time, whether the login attempt succeeds or fails.

By exposing credential abuse early, Memcyco helps enterprises prevent unauthorized access before it escalates into account takeover or downstream fraud.

How it works:

• Memcyco identifies credential stuffing attempts as they unfold, based on abnormal login behavior and signs of credential misuse.

• On the genuine site, it monitors device behavior, login patterns, and session signals to distinguish legitimate users from automated attacks.

• Decoy credentials are injected to expose stolen-data reuse and immediately neutralize credential replay attempts.

• When threats are detected, Memcyco provides real-time insights into attack sources, targeted accounts, and high-risk devices, giving enterprises the ability to act before damage occurs.

Memcyco gives enterprises visibility and control at the moment credential-based fraud begins.

Related reading

• 5 of the Biggest Retail Account Takeovers in Recent Years (And How They Could Have Been Stopped)
• How Browser-Level Signals Prevent Credential Stuffing
• Phishing Site Detection & Takedown: What to Look For