A credential-based attack is where a cybercriminal exploits stolen credentials to gain unauthorized access to an application, system, or network. With this initial access, they can move laterally to exfiltrate sensitive data or launch ransomware attacks, among other things.
These types of attacks focus on the exploitation of the credentials themselves regardless of how they were obtained. But, the tricky part? There are many variations of credential-based attacks, making detection and mitigation extremely difficult without a comprehensive security tech stack.
How credential-based attacks work
A credential-based attack typically involves the following steps:
1) Obtain credentials: Cybercriminals use various tools and attack methods for credential theft. Types of malware that harvest credentials include infostealers, remote access trojans (RATs), and browser hijackers. Phishing is the most common attack method for deploying malware. Around 80% of phishing campaigns aim to steal credentials. Attackers can also buy large lists of stolen credentials from dark web marketplaces.
2) Validate credentials: Once an attacker obtains credentials, they usually test them on multiple applications or platforms using automated tools. They use attack methods such as credential stuffing, password spraying, or brute force to find working combinations of usernames and passwords.
3) Gain initial access: When the hacker finally finds a username and password combination that works, they gain initial access to the system. They can then spend some time learning about different areas of the system and figuring out how to gain access to them.
4) Move laterally: After gaining initial access, the attacker can begin lateral movement, navigating the compromised system with specific goals in mind. They may aim to gain higher access privileges or exfiltrate valuable data. They could launch extended attacks like advanced persistent threats (APTs) or ransomware attacks.
Cybercriminals today have access to advanced automated tools and AI models that allow them to launch massive and fast-moving credential-based attacks, and in many variations.
Common variations of credential-based attacks
Credential-based attacks come in many forms, including:
- Account takeover (ATO): ATO involves a cybercriminal seizing control of a user’s account and using that access for various activities, such as leaking sensitive data, draining funds, and executing unauthorized transactions.
- Authentication bypass: An approach where the attacker exploits flaws or vulnerabilities in authentication processes to gain unauthorized access to a system or application.
- Brute force: This attack involves a criminal forcing their way into accounts through trial and error. The hacker tries different variations of usernames and passwords until they find a combination that allows them to gain access to an account.
- Credential replay: Using this complicated method of attack a cybercriminal can make requests to a system or application that appear as though they come from a legitimate user. A credential replay attack has three main phases:
- Capture credential data in transit
- Copy the captured data to a storage tool
- Resend the intercepted data to the network
- Credential stuffing: Where an attacker uses automated tools to repeatedly attempt to hack different accounts with the same login information victims have used on other sites. The leaked credentials used for a credential stuffing attack typically come from data breaches, the data often made available on dark web marketplaces.
- Keylogging: Spyware that records and logs the keystrokes a user makes on their computer. Hackers use keyloggers to obtain sensitive information from compromised devices, such as usernames, passwords, and credit card numbers.
- Password spraying: A method of attack where a hacker tries to break into multiple accounts on the same application or platform by using one common password. Password spraying helps attackers avoid account lockouts.
- Session hijacking: Involves a hacker taking control of a user’s session. There are several ways to hijack a session, including:
- Steal the session ID using various methods, such as cross-site scripting (XSS)
- Launch a brute force attack, trying multiple IDs until one works
- Deploy a Browser in the Middle (BitM) attack using a transparent proxy and a phishing domain.
This is not a comprehensive list. Cybercriminals have many more options for conducting credential-based attacks. Organizations need to implement tools that will detect various attack methods and ensure credential security.
Defending against attacks based on credentials
The average cost of a data breach due to stolen credentials or credential compromise was $4.81 million in 2024, according to IBM’s 2024 Cost of a Data Breach Report.
Defending against costly credential-based attacks requires a security tech stack that includes a wide range of tools and approaches — from phishing-resistant MFA and passwordless authentication to threat hunting and cyber threat intelligence (CTI).
One of the most crucial tools to include in your security tech stack is real-time dark web monitoring. A dark web monitoring tool continuously scans dark web data sources, enabling teams to detect leaked credentials before attackers can exploit them. Teams can also identify compromised credentials, correlating them with indicators of compromise (IOCs) to predict and plan for credential-based cyberattacks.
