Life After a Breach: Where Stolen Data Goes

When a data breach occurs, the stolen information doesn’t just vanish—it becomes a valuable asset in the cybercriminal underworld. Once credentials, financial details, or personal information are revealed, they are absorbed into a sprawling black market where cybercriminals barter, sell, and misuse them for financial gain. From dark web marketplaces to phishing schemes and identity fraud, breached data fuels a wide range of cyber threats. But where exactly does stolen data go, and how is it used?

In this blog, we’ll uncover the secretive world of post-breach activity, revealing how cybercriminals exploit stolen data for profit, and how individuals and businesses can defend against these threats.

Where Does Your Stolen Data Go?

Stolen data often ends up in various locations across the internet, depending on the intentions of the perpetrators. Here are the primary destinations where such data might be distributed or utilised:

1. Dark Web Marketplace: one of the most notorious spots for stolen data is the dark web. This part of the internet is not indexed by traditional search engines and requires specific software to access. Here, personal information, credit card details, and other sensitive data can be sold to the highest bidder.
2. Forums and Chat Rooms: not all trading of stolen data happens in dark marketplaces. Some data exchanges take place in more accessible forums and chat rooms that cater to specific types of cybercriminals. These venues might be less secure than marketplaces and vary greatly in terms of access controls, usually open to strictly invitation-only.
3. Private Networks: newly stolen data might be shared or sold within private networks of criminals. These are typically more elusive and harder to infiltrate, involving trusted relationships among experienced hackers and communication through encrypted messaging.
4. Data Dump Sites: in some cases, stolen data is simply dumped publicly on the internet where it can be accessed by anyone. This can include personal data dumps to larger scale data leaks involving sensitive corporate or governmental information.

How Cybercriminals Use Your Data

There are many ways that cybercriminals use the leaked information from data breaches, here are some of the main ones.

Credential Stuffing

The most prominent use of this data is trying to break into accounts using credential stuffing, where an attacker tries known emails and passwords on websites to gain access. Popular targets are email providers because once you gain access to an email, you can often reset the passwords on any other sites. If the email account falls, the attacker now gets access to almost all your other accounts, even if they all have very strong passwords.

Another popular target are sites that require some kind of subscription or payment, like Netflix or other accounts that have some kind of resale value. The logic being “Why pay £100 per year for Netflix when you can just buy access to someone else’s account for £10?”.

Account Takeovers

Another use is attempting to gain access into a company’s system, often targeting high-privileged employees. A very recent instance of this happening was when a company called “Snowflake” had a breach in 2024. Because Snowflake is a cloud storage company, over 100 of their business customers were affected and caused chaos. Just a single employee’s leaked email and password caused over 100 company’s data to be leaked, including all of the telecom company AT&T’s phone records, which they then paid the hacker $370,000 to delete.

This is the main reason why many modern companies are so strict about phishing training. In a company of hundreds or thousands of employees, it only takes a single employee to fall for a phish and the hackers are in!

Email Crimes

A very common way that breached data is used, is for email crimes such as phishing, extortion, or referral link spamming.

Phishing is where cybercriminals attempt to deceive a user into clicking on a malicious link or giving over some kind of sensitive information like credentials or banking information, commonly pretending to be a bank or postal company. “Your package has been held up at the border patrol and needs £2.99 to release it”, only for that credit card to be completely drained by a cybercriminal.

Extortion/Blackmail is a method that is quickly becoming very popular, where gathered data like full names, addresses and other personal information is used to pretend that the cybercriminal has more access than they really do and pretend that they know or have something bad about the person, like an embarrassing search history or webcam photo. This is never true but is just made to scare people into giving away hundreds of pounds to “keep the secret” and not release this information to friends and family (despite the attacker not actually having any of this information).

Referral Link Spamming is potentially the most common use of breached data, where someone will spam several emails to tens of millions of people about a real product, claiming many falsities about the product, then when the user creates an account with the cybercriminal’s link, they get some money for referring the new user. This makes up most of people’s junk emails. These kinds of emails often look like “Claim your 30 Free Spins!” or “Don’t miss out: Claim Your Bonus Now!”. Due to the person sending the emails not technically being part of the company, they are not held to the same misleading advertising standards and can say whatever they like to get the clicks.

The Dark Web Marketplace

The dark web operates as the black market of hidden internet, where stolen data is bought and sold with ease. After a data breach, cybercriminals don’t just hoard the information—they monetize it. From login credentials and credit card details to full identity profiles, this data becomes a valuable commodity in underground forums and illicit marketplaces. Using cryptocurrency for anonymous transactions, hackers auction off breached records in bulk, powering a thriving cybercrime economy.

The price of your data on the dark web

Research carried out in 2023 by news website Privacy Affairs looks at the average prices of various goods and services sold by cybercriminals on the dark web:

Category	Most expensive data point in category	Avg. dark web Price
Credit card data	Credit card details, account balance up to $5,000	$110
Credit card data	Stolen online banking logins, minimum 100 on account	$40
Payment processing services	Verified Stripe account with payment gateway	$1,200
Crypto accounts	Bitit.io verified account	$450
Social media	Hacked Gmail account	$60
Social media	Hacked Facebook account	$25
Hacked services	Bet365 account	$35
Hacked Services	Spotify account	$10
Forged documents (scans)	New York driver’s licence	$60
Forged documents	UK passport template	$22
Forged documents (physical)	Maltese passport	$4,000
Forged documents (physical)	EU driver’s license	$2,000

 

The Aftermath of a Breach

A data breach can have far reaching consequences for both an individual and a business. The impact of exposed sensitive data can be immediate or slowly unfolding over time, ultimately leading to financial loss, reputational damage, operational disruptions, legal troubles and regulatory fines, and long-term security issues.

• Financial Loss – one of the most immediate and measurable impacts from a data breach. Costs can include regulatory fines for non-compliance with GDPR. There will be costs to investigate the breach and to upgrade security measures. Lost revenue will come as customers lose trust and take their business elsewhere. For individuals, there is the risk of fraudulent transactions, access to personal bank accounts and identity theft.
• Reputational Damage – a data breach can severely damage an organisations reputation. Customers will quickly lose confidence knowing the company has failed to protect their data. The negative media coverage will damage brand perception, making recovery difficult. Other companies may hesitate to collaborate with a breached organisation due to security concerns.
• Operational Downtime – a data breach can have a major disruption on an organisations ability to operate efficiently. It may lead to a company having to shut down networks or services for a period of time. Employees could well be locked out of services and having to revert to manual processes. IT teams will be focussed on recovery and not on regular operations.
• Legal Implications – failure to protect customer or employee data comes with legal consequences. Regulatory authorities may launch an inquiry onto compliance failures. Customers or employees may decide to take legal action seeking compensation. A breach could be violating a contract with partners, resulting in penalties. Businesses must ensure they comply with data protection laws and have an incident response plan in place to mitigate legal risks.
• Loss of Sensitive Data – once sensitive data is exposed, it may never be recovered. This will result in ongoing risks of identity theft and fraudulent activities using personal data. Bad actors could use stolen passwords for credential stuffing and trying to access other accounts. Its possible cybercriminals could exploit company data to gain financially.

Steps to Take After a Breach

Whether you are a business or an individual, discovering that your data has been compromised can be very distressing. However, the steps you take immediately following a breach are critical for limiting any potential damage and restoring security. Here’s what you should do:

1. Change Your Passwords: start by changing the passwords of all compromised accounts. If you’ve used the same password on other platforms, change those as well to prevent a chain reaction of unauthorised access, making them unique for each account
2. Improve Security Measures: both individuals and organisations can add an extra layer of security by enabling multifactor authentication (MFA) on all accounts. This provides an additional defence, making it more challenging for attackers to gain unauthorised access even if they have your password. For an organisation, post-breach is a critical time to review and strengthen cyber security measures.
3. Monitor Your Account: regularly monitor your financial accounts for any unusual activity, as early detection can help minimize the impact of a breach. Stay vigilant for unauthorised access to compromised accounts and remain cautious of potential phishing scams.
4. Notify Affected Parties: a business must follow legal requirements and inform customers, employees and partners of any breach as well as notifying the relevant authorities about the breach.

Both businesses and individuals must take quick action, staying proactive and informed is key to mitigating the risks of a data breach.

Moving Forward Post-Breach

A data breach is never just a one-time event—it sets off a chain reaction that can have long-lasting consequences for individuals and businesses alike. Once stolen data enters the dark web, it can be bought, sold, and exploited in ways that extend far beyond the initial breach. From identity theft and financial fraud to corporate espionage and credential stuffing attacks, the risks are ongoing.

Businesses must prioritise robust cybersecurity strategies, from implementing strong access controls to continuous monitoring for compromised data. Individuals can take proactive steps, using strong passwords, enabling multifactor authentication, and staying alert to potential scams.

Awareness and action are our best defences and by understanding where stolen data goes and how it is used, we can better protect ourselves. Cybersecurity isn’t just about preventing breaches; it’s about being prepared for what happens next.