What is Credential Stuffing?
Credential stuffing is a type of cyber attack in which large sets of stolen credentials from one platform are used to gain unauthorized access to user accounts on another platform. Using bots or automation tools, hackers test out millions of credential combinations on target websites until they can successfully log in to accounts.
This method operates on the premise that many individuals reuse their login credentials across multiple platforms. Unlike targeted attacks, credential stuffing is a numbers game – it relies on the sheer volume of attempts, assuming that some will inevitably succeed.
The Difference Between Credential Stuffing Attacks and Brute Force Attacks
The main difference between credential stuffing and other types of attacks lies in its specificity and methodology. For instance, brute force attacks involve guessing login information by trying numerous possible combinations, often without any foundational data. On the other hand, credential stuffing uses pre-existing username and password combinations, which have often been exposed in previous breaches. This approach is more surgical compared to the blunt instrument of brute force attacks.
Comparatively, phishing attempts to deceive individuals into voluntarily providing sensitive information by masquerading as a trustworthy entity in electronic communication. In contrast, credential stuffing does not require direct interaction with the user; it exploits the user’s potentially lax security practices across different services.
How Do Credential Stuffing Attacks Work?
Credential stuffing attacks unfold in a series of steps that allow cybercriminals to exploit user accounts at scale:
- Collection of Stolen Credential Collection
Credential stuffing attacks begin with a database of compromised login details. These are often obtained from previous database breaches and may be freely available on the internet or sold on dark web marketplaces. - Automation of Attack Using Bots
Using bots or specialized credential stuffing software, attackers systematically attempt to log in to multiple accounts across targeted sites with the list of stolen credentials. This is typically done over a distributed network to minimize the chances of being blocked by any rate-limiting defenses.
- Access and Exploitation
Successful login attempts—where a stolen username and password pair match an existing account on the service—are recorded. The attacker can then exploit these verified accounts for fraudulent activities, data theft, or secondary attacks.
Through this combination of vast numbers of stolen credentials, powerful automation tools, and the distributed nature of botnets, attackers can test millions of credentials across numerous sites, all with minimal effort and risk. This method's simplicity and high success rate underscore the need for robust defenses against credential stuffing attacks.
The Impact and Consequences of Credential Stuffing
How Credential Stuffing Attacks Affect Individuals
- Financial Loss
Individuals may find unauthorized transactions made using their accounts, leading to direct financial loss. In severe cases, attackers can drain bank accounts or make fraudulent purchases.
- Privacy Breach
Personal information, including email addresses, phone numbers, and even addresses, can be exposed, leading to privacy violations and potential risks of identity theft.
- Identity Theft
With access to personal details, attackers can impersonate individuals, leading to identity theft. This can have far-reaching consequences, such as false legal accusations, debt accumulation, and a lengthy recovery process.
- Credit Score Damage
Unauthorized financial activities can adversely affect an individual's credit score, impacting their ability to secure loans, mortgages, and other financial products in the future.
How Credential Stuffing Attacks Affect Organizations
- Financial Losses
Organizations face direct financial losses due to fraudulent transactions. Additionally, they incur costs in investigating the breach, implementing security measures, and compensating affected customers.
- Loss of Customer Trust
A breach can lead to a significant loss of trust among customers and clients. This can result in a decline in user engagement, customer churn, and difficulty in attracting new customers.
- Brand and Reputation Damage
The long-term impact on an organization’s reputation can be severe. Rebuilding customer trust and brand image post-attack is challenging and can impact future business prospects.
- Legal and Compliance Issues
Organizations might face legal consequences, including fines and sanctions if found non-compliant with data protection regulations. They may also face lawsuits from affected customers.
- Increased Security Investments
Post-breach, organizations often need to invest heavily in upgrading their cybersecurity infrastructure, implementing more robust authentication methods, and ongoing employee training, all of which involve additional costs.
- Operational Disruption
Responding to and recovering from an attack can disrupt regular business operations, leading to productivity loss and potential service downtime.
Examples of Credential Stuffing Attacks
- Chick-fil-A
In March 2023, US fast food chain Chick-fil-A released a statement confirming that they had been targeted by a credential stuffing attack, resulting in hackers breaching around 71,000 Chick-fil-A accounts. According to Chick-fil-A’s investigation, hackers attacked over two months using credentials obtained from a third-party source
Chick-fil-A accounts contained the following personal information of customers:
- Name
- Email address
- Chick-fil-A One membership number and mobile pay number
- QR code
- Masked credit/debit number
- Chick-fil-A credit
In response to the incident, affected customers were forced to reset their passwords, while Chick-fil-A froze account credits and removed any stored payment information. Customers were then given additional rewards as an apology from the fast food chain.
- Paypal
In January 2023, PayPal reported that it had been breached by a credential stuffing attack that occurred earlier in December 2022. As a result, attackers gained access to almost 35,000 user accounts, including the following information:
- Full names
- Birthdays
- Postal addresses
- Social security numbers
- Tax identification numbers
- Transaction histories
- Linked credit or debit card details
- PayPal invoicing data
In response, PayPal reset the passwords of affected users and took steps to limit hackers’ access to the platform. Paypal assured users that the attackers were not able to carry out any transactions from the accounts they had breached. Users who were impacted by the incident were given a free 2-year subscription to an identity monitoring service from Equifax.
