Chief information security officers (CISOs) and other security leaders have heard the term darknet — and typically avoid it with good reason. When used carefully and securely, however, it is an invaluable source of threat intelligence data. But what’s really available under the surface of obvious online resources? How do organizations access this twilight technology trove? And what steps can they take to shine a light on potential security threats?

Here’s a how-to guide for (safely) navigating the darknet.

Blinded by the Light

While attackers may hide in the darknet, also called the dark web, their impacts are most often felt on the surface as cybercriminals attempt to infect corporate networks and compromise critical devices. What’s more, these impacts are getting worse: As noted by the “IBM X-Force Threat Intelligence Index,” 2018 saw 450 percent growth in cryptojacking attacks while the average number of vulnerabilities per organization skyrocketed to more than 1,400. And, according to Malwarebytes’ “2019 State of Malware,” “tricky” ransomware and corporate “mega-breaches” are on the rise as hackers develop new, more sophisticated techniques. As a result, data breaches now cost more than $3.9 million on average with more than 25,000 records compromised.

For CISOs and CSOs, this evolving threat landscape makes it easy to get blinded by the light, focusing on end results without considering the underlying cause. In fact, darknet databases offer the perfect proving ground for malicious actors to share new ideas, test new threat vectors and select top targets — and offer opportunity for an infosec advantage.

What Lies Beneath the Surface Web?

So what exactly is the darknet? What’s available? And how does it work?

Three terms matter here: surface web, deep web and dark web.

• The surface web is what most people mean when they say “the internet.” The surface web contains publicly indexed, searchable sites — online resources that can be found and accessed via typical search engines.
• The deep web contains everything that isn’t publicly indexed. Often confused with the darknet, the deep web is mostly composed of benign sites that are password-protected or otherwise not available to the general public. Databases of personally identifiable information (PII), user accounts and financial transactions are found in the deep web. The deep web is also massive: It’s 400–550 times larger than the surface web and continuously growing thanks to the influx of secure big data.
• Sites on the dark web aren’t just hidden from view, they’re also encrypted and anonymized to hide their origins, locations and creators. As noted by Security Boulevard, the term was originally used for ARPANET computers that could receive messages, but didn’t transmit data in return, effectively rendering them “dark.” The darknet is not criminal by nature, supporting both legitimate content that requires enhanced security and illegal activities that shy away from scrutiny — but it does provide criminals a safe place from prying infosec eyes.

Many users conceptualize the darknet as a mirror image of the World Wide Web (WWW), but recent research found that “unlike the WWW, the dark web is a place of isolation.” Silos, not connected systems, make up the bulk of darknet destinations.

Darknet Encryption Does Not Guarantee Network Safety

Getting to the darknet requires more than a browser and a search engine. Specialized tools — known as overlay networks — use purpose-built software, configurations and communications protocols to gain darknet access and ensure user anonymity.

It’s worth noting that the dark web isn’t a singular system like the loosely connected surface web. In fact, there are four well-populated darknets: the Tor network, I2P, Zeronet and Freenet. Tor, which stands for “the onion router,” uses multiple layers of encryption to reveal multiple relays and ensure secure data transmission. Tor data is also sent bidirectionally, using the same “tunnel” to both send and receive information. I2P, meanwhile, facilitates peer-to-peer file sharing by combining user data sets to prevent unpacking and inspection. Unlike Tor, I2P uses a unidirectional tunnel.

For CISOs considering a trip to the dark web, it’s critical to remember that essential cybersecurity best practices still apply, since layered encryption does not guarantee network safety from malicious attacks. To minimize risk, it’s essential to protect networks from potential damage with reliable virtual private networks (VPNs) and in-house encryption. Once excursions to the web’s underbelly are complete, it’s worth taking a step back to evaluate the veracity of any data obtained and conduct a thorough review of potential network vulnerabilities to address any artifacts left behind after inter-web investigations.

5 Steps for Navigating the Darknet

Once darknet access is achieved, how can organizations use shadow sites to glean threat intelligence data? Start with these five steps:

1. Listen in — Gaining access to darknet forums and databases typically includes a vetting process. Here, it’s worthwhile to leverage the services of skilled white hat hackers who can vouch for infosec actors and get them in the digital door. Once inside, companies are best served by paying attention as threat actors discuss potential zero-day or open source vulnerabilities. Listening in gives organizations a head start on assessing their networks for potential weak spots.
2. Find out — Often, dark web nodes contain data dumps from hacked surface websites or user accounts. Collecting and parsing this data can help companies find out what type of information is currently on hacker hit lists. Are attackers prioritizing healthcare data? Credit histories? Online purchasing habits? As CSO Online noted, effectively utilizing this data typically requires four steps: automatic parsing of data sources, normalization and deduplication, validation, and context-based enrichment to deliver business-specific insights.
3. Look around — Use the darknet to search for your company name, current corporate email address format or the names of C-suite executives. While this requires multiple searches across several dark web networks, their relatively small size makes it worth the time and effort. Finding mentions of your organization helps determine if you’re a target and, more importantly, if you’ve been compromised.
4. Build up — New exploits cut their teeth in the darknet, from attacks that rely on open-source software vulnerabilities to zero-day flaws in new applications. Seeing these threats in action before they hit your network gives you time to build better defenses.
5. Dig down — The easiest way for attackers to breach your network? Employees. By digging down into the forums and chat groups of the darknet, you can discover common human-centric weak points in typical security controls and make critical adjustments. For example, IT Business Edge noted that attackers are especially talented at “connecting the dots” across surface web social media sites to create targeted phishing attacks and malware strains. Digging into the dark web helps infosec pros design user education programs that speak directly to emerging threats.

Out of the Darkness

Valuable threat intelligence data lives on the darknet. While CISOs are understandably reticent to turn off the lights, securely accessing the dark web can help organizations overhear cybercriminal conversations, find actionable data, look for evidence of compromise, build better defenses and uncover critical user risks.