Credential Abuse refers to the malicious use of stolen or compromised credentials – usernames, passwords, API keys, tokens, and similar secrets – to gain unauthorized access to systems, accounts, and data. It is distinct from credential theft, which is the initial act of stealing the credentials. A useful analogy: credential theft is a robber stealing the key to your house, while credential abuse is using that key to enter and rifle through your belongings. Abuse is the exploitation stage that follows theft.
Credentials are compromised through many routes – phishing, malware, data breaches, and interception on unsecured networks (such as man-in-the-middle attacks). A wide range of credential types can be targeted: passwords, one-time passwords, security tokens, API keys, SSH keys, and OAuth tokens, along with security questions and device-bound authentication data. Once obtained, these credentials become the raw material for abuse.
Credential abuse typically manifests through techniques such as credential stuffing and brute-force attacks (automatically testing stolen credentials against login endpoints), account takeover, and lateral movement within a network once an initial foothold is established. Because the credentials are valid, the resulting access looks legitimate, which makes credential abuse hard to detect – the attacker appears to be an authorized user. This trust is exactly what makes it powerful: attackers can steal data, impersonate services, conduct fraud, and move deeper into systems while blending in with normal activity.
APIs are heavily exposed to credential abuse because they authenticate using keys and tokens that, if leaked (for example, hard-coded in client apps or exposed in repositories), grant direct programmatic access. Non-human and machine identities multiply the number of credentials in play.
Defending against credential abuse combines prevention and detection: strong, unique credentials and password managers, multi-factor authentication, careful secrets management and rotation, least-privilege access, monitoring for anomalous logins and behavior, and bot management to counter automated credential-testing. Because abuse hinges on valid credentials, behavioral analytics that recognize when a legitimate credential is being used illegitimately are especially important.