What Is Credential Stuffing?

Credential stuffing is a cyber threat that accesses online user accounts using stolen usernames and passwords. As a form of brute force attack, credential stuffing involves cyber-attackers using automation to attempt various combinations of usernames and passwords until they pinpoint a successful pairing.

Particularly prevalent across financial services accounts, credential stuffing attacks have become a preferred cyber-attack among threat actors. According to Verizon’s Data Breach Investigations Report, over 80% of hacking-related breaches involve using lost or stolen credentials. Not only is credential stuffing one of the most common causes of data breaches, but data from SpyCloud indicates that 64% of people reuse the same password on multiple accounts, making them especially vulnerable to such attacks.

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How Does Credential Stuffing Work?

In a credential stuffing attack, threat actors utilize stolen or leaked usernames and passwords obtained through data breaches or purchased on the dark web. They simultaneously employ automated tools to test these credentials on multiple websites, banking on people’s propensity to reuse their login details across different platforms.

Automation plays a crucial role in credential stuffing attacks. Cybercriminals utilize botnets, which are networks of compromised computers, to automate testing username-password combinations on targeted websites. This approach enables them to rapidly assess a large number of credentials over a brief time period.

Credential stuffing attacks typically involve two phases: validation and exploitation. In the validation phase, botnets test the stolen username-password pairs to identify successful matches. Once a successful match is found, the attacker proceeds to the exploitation phase.

In the exploitation phase, the validated credentials are used for various malicious purposes. This can include identity theft, fraudulent transactions, or selling compromised accounts on darknet markets. The actions taken depend on the type of account breached, whether a personal email account or a corporate system.

Credential Stuffing vs. Brute Force Attacks

Both types of cyber-attacks–credential stuffing and brute force attacks–try to access user accounts without authorization, yet they operate in unique ways. Here are the main differences between the two:

  • Methodology: Brute force attacks attempt to guess passwords by trying different combinations of characters until the correct password is found. In contrast, credential stuffing attacks use stolen pairs of usernames and passwords from a data breach or dark web purchase to gain unauthorized access to user accounts on other systems through automated login requests.
  • Intelligence: Credential stuffing attacks use more intelligence because they use previously discovered credential pairs, whereas brute force attacks use random characters or common password suggestions.
  • Scale: The scale of credential stuffing attacks are typically large, with thousands to millions of previously discovered credential pairs used to automate logins. Brute force attacks can also be carried out on a large scale but are often limited by the complexity of the passwords.
  • Prevention: Preventing brute force attacks typically involves implementing measures such as rate limiting, account lockout policies, and strong password policies. Preventing credential stuffing attacks involves implementing multi-factor authentication, monitoring suspicious login activity, and regularly changing passwords.

While both credential stuffing and brute force attacks have similar intentions, they differ in their methodology, scalability, and prevention measures. In turn, organizations must understand the differences between these attacks and implement the appropriate security measures to prevent them.

Impact of Credential Stuffing

Credential stuffing is a cyber-attack with severe implications for organizations. Given credential stuffing attacks employ stolen login info, the outcome can result in considerable financial loss, harm to an organization’s reputation, and possible legal repercussions. Many of these effects can have overlapped implications.

Compromised Accounts and Data Breaches

One of the most critical impacts of credential stuffing attacks is the compromise of user accounts. Malicious actors exploit reused or weak credentials to gain unauthorized access to individual accounts. This can lead to sensitive data and information falling into the wrong hands, potentially exposing personal and financial details. Such data breaches erode trust in the affected businesses and can lead to severe repercussions for both the company and its customers.

Account Lockouts and User Frustration

Credential stuffing attacks bombard authentication systems with large volumes of login attempts. As a result, legitimate users may face frequent account lockouts due to multiple incorrect login attempts. The effect causes inconvenience and can frustrate the user, leaving them with a negative user experience. Long-lasting account lockouts can mean customers seeking alternative services, impacting the business’s reputation and bottom line.

Ransomware Threats and Extortion

In some instances, credential stuffing attacks may serve as a gateway for more devastating cyber threats. Once attackers gain access to a system, they may deploy ransomware, encrypting critical data and demanding a ransom for its release. Falling victim to such extortion can be financially crippling for businesses, as they must decide between paying the ransom or losing access to crucial data or having it exposed or misused in some other way.

Financial Impact

Credential stuffing attacks can lead to substantial financial losses for organizations. When attackers gain unauthorized access to user accounts, they can exploit them for various purposes, such as making fraudulent purchases, draining bank accounts, or conducting identity theft. The financial impact can be devastating, with businesses facing direct financial losses and potential liabilities for failing to protect their users’ accounts. In 2020 alone, the financial services sector suffered $3.4 billion in losses due to such attacks.

Reputational Damage

Credential stuffing attacks can severely damage a company’s reputation. Compromised user accounts erode trust in an organization’s ability to protect sensitive information. Customers may be uncertain of the firm’s safety measures and opt to take their business elsewhere. Additionally, news of a credential stuffing attack can spread quickly, further tarnishing the company’s reputation and making it difficult to regain trust.

Fines Under GDPR

If your organization operates within Europe or handles European citizens’ data, note that GDPR (European Union General Data Protection Regulation) violations may incur hefty fines depending on the severity and nature of the non-compliance. Non-compliance with the GDPR, including inadequate protection of user accounts from credential stuffing attacks, can lead to significant financial penalties. These fines are based on the severity and nature of the non-compliance, emphasizing the importance of maintaining robust password hygiene practices and implementing strong security measures to prevent credential stuffing.

Other jurisdictions have similar rules and related fines.

The impacts of credential stuffing attacks can be severe and far-reaching. Organizations must understand the implications of credential stuffing and take proactive steps to protect their digital assets and infrastructure. By implementing multi-factor authentication, monitoring for suspicious activities, and educating users about password security, businesses can mitigate the risks associated with credential stuffing and safeguard their reputation and financial well-being.

How to Prevent Credential Stuffing

Preventing credential stuffing attacks is critical on both a personal and commercial level. There are strategies that organizations and end-users alike can leverage to minimize such cyber-attacks. Most credential stuffing attacks can be effectively mitigated by implementing the following cybersecurity measures:

  • Use unique passwords for each service: Using unique passwords for each service can prevent cybercriminals from using the same stolen credentials across multiple accounts.
  • Use multi-factor authentication: Multi-factor authentication (MFA) is an additional layer of security requiring more than one form of authentication, such as a password and a fingerprint or a one-time code.
  • Use a web application firewall: A web application firewall (WAF) protects against credential stuffing attacks by blocking suspicious login attempts and identifying attack patterns.
  • Monitor for suspicious login activity: Regularly monitoring for suspicious login activity can help detect and prevent credential stuffing attacks before they can cause damage.
  • Educate users: Educate users with security awareness training about the risks of credential stuffing, the importance of using strong passwords, and how enabling MFA can prevent successful attacks.
  • Use a bot management platform: A bot management platform can prevent credential stuffing attacks by detecting and blocking automated login attempts.

Overall, preventing credential stuffing attacks requires a combination of technical and non-technical measures. By implementing the proper cybersecurity measures, organizations can minimize the chances of becoming credential stuffing attack victims.

How to Detect Credential Stuffing Attacks

While prevention is critical for any entity or account, detection is especially crucial for organizations aiming to mitigate credential stuffing attacks. It’s a matter of vigilance and the right tools.

Monitoring Login Attempts

The initial step towards identifying credential stuffing attacks involves closely observing login attempts. A sudden spike in failed logins from one or multiple IP addresses may signal an ongoing attack. It’s crucial to scrutinize patterns such as rapid-fire login attempts or simultaneous logins using different credentials.

Analyzing Traffic Origin

Cybercriminals often employ proxy networks or VPNs to hide their location during credential stuffing campaigns. Consequently, analyzing traffic origin is essential to spot these threats. Excessive traffic originating from countries where you have no customers could indicate an imminent attack.

User and Entity Behavior Analytics

User and entity behavior analytics (UEBA) also play a significant role in detecting credential stuffing attacks. This includes studying typical user behaviors like usual login times, device types used for access, and frequency of password changes and flagging any deviations from these norms as potentially suspicious activities.

Recognizing common signs can aid in early detection, which is vital for minimizing potential damage.

How Proofpoint Can Help

Proofpoint provides several cybersecurity solutions to help protect against credential stuffing attacks. Some of the most powerful include:

  • Security Awareness Training: Through cybersecurity education and security awareness training solutions, Proofpoint emphasizes the importance of password security and encourages users to avoid reusing passwords across different sites. Using unique passwords for each site can significantly reduce the risk of credential stuffing attacks.
  • Cloud Account Defense: Proofpoint Cloud Account Defense uses advanced threat intelligence and machine learning to detect suspicious login attempts and other signs of account compromise. When a suspicious login attempt is detected, Cloud Account Defense provides detailed information about the attack, including the source IP address, the type of attack, and the targeted user account.
  • Email Security and Protection: The Proofpoint Aegis email security platform uses multilayered detection techniques, including reputation and content analysis, to help defend against constantly evolving threats. Powered by NexusAI, Proofpoint's Email Protection solution accurately classifies various types of email and detects and blocks threats that don't involve malicious payload, such as business email compromise (BEC).
  • Data Loss Prevention: Proofpoint Enterprise Data Loss Prevention (DLP) solutions use advanced content analysis to identify sensitive data, such as personally identifiable information (PII), financial data, and intellectual property. It monitors data movement across various channels, including email, cloud, endpoint, and web, to detect and prevent unauthorized data exfiltration. Equipped with real-time alerts, DLP solutions also enforce policies to prevent unauthorized data access and use, such as blocking the transmission of sensitive data outside the organization or encrypting sensitive data in transit.

While Proofpoint does not offer a direct solution specifically tailored for credential stuffing attacks, its range of cybersecurity solutions can collectively contribute to mitigating the risks associated with them. For more information, contact Proofpoint.

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