The last few decades have seen a significant increase in the operational complexity of cybercrime gangs. This has created something akin to an industry, where each group specializes in a specific part of the attacks: some only breach networks, others focus on malware development, and some deal exclusively in data trading, among other roles.

Amidst so many modes of operation, forums on the deep and dark web have become true marketplaces for leaked data, where corporate credentials, personal information, and sensitive assets are traded like commodities. And what starts as a simple leak can quickly escalate into an attack on your infrastructure.

 

From Theft to Sale: The Leaked Data Cycle

Every leak begins with an extraction. This can happen through phishing or other social engineering techniques, through malware like infostealers, or even via insiders. Sensitive data is then extracted from organizations and published or sold on closed channels. Platforms like Telegram, forums like the now-defunct BreachForums, and clandestine marketplaces are the main stage for these negotiations.

A central role in this cycle is played by Initial Access Brokers (IABs)—operators specialized in breaching companies and selling access to their networks. They have specialized in opening the door and leaving a crack available for the highest bidder, whether they are ransomware groups, APTs, or other malicious operations.

The connection between leaked data and targeted attacks is not hypothetical—it is an operational reality for cybercriminal groups, manifesting in various ways, such as:

• Credential-Based Ransomware: In campaigns like those from 8Base or RansomHouse, many infections started with VPN or RDP credentials obtained from dark web forums.
• Business Email Compromise (BEC): Corporate fraud attacks often start with complete email inbox databases, which reveal internal communications and transaction patterns.
• Social Engineering and Spear Phishing: HR information, organizational charts, and personal data allow for the creation of highly convincing messages, often using specific employee names and internal details to appear more credible.

Today’s leaks are not like those of previous years. Criminal groups are automating data exploitation, using generative AI to produce social engineering content at scale, and creating tools to structure and enrich stolen data, facilitating direct integration into attack tools. Furthermore, leaks are being used not only for financial gain but also as instruments of political influence and disinformation.

Protecting against the impact of leaked data requires more than just resetting passwords. It demands strategy, visibility, and readiness. Some recommended actions include:

• Mapping and classifying the organization’s most sensitive data.
• Adopting brand and leak monitoring solutions.
• Having a clear leak response policy that covers not only technical mitigation but also communication with stakeholders.
• Establishing partnerships with companies or consultancies specialized in Cyber Threat Intelligence (CTI) for continuous support.

How Resonant Acts to Mitigate Risk

Resonant’s Cyber Threat Intelligence (CTI) area plays a fundamental role in the early detection of leaks and in understanding their potential impact. With automated monitoring techniques and human analysis, our CTI can:

• Identify relevant leaks in real-time, correlating data with company assets.
• Associate leaks with known TTPs of active groups, anticipating attack vectors.
• Disseminate actionable alerts to areas such as offensive security, SOC, and GRC.
• Integrate this information into the defense ecosystem, enriching SIEMs, EDRs, and response workflows with additional context.

This intelligence creates the conditions to react even before an attack materializes. The reality is clear: leaked data isn’t a distant problem—it’s the beginning of an increasingly common attack chain. Ignoring its existence is like walking blindfolded through a minefield.

Does your organization already monitor leaks in real-time? Does it correlate data dumps with your digital inventory? If the answer is “no,” it might be time to review your strategy.

Talk to our team and discover how implementing an intelligence approach centered on leaked data can be the difference between a prevented incident and an irreversible loss.