Monitoring dark web traffic

Robert Fitzsimons at Searchlight Cyber explains why traffic between the dark web and your network is almost always a bad sign

 

Traffic monitoring is a crucial aspect of daily security workflows for many organisations. Vigilant networking and security teams act as sentries, constantly watching over their network’s activity for any signs of anomalous traffic patterns that might indicate potential threats.

 

However, all too many security teams are not actively monitoring traffic originating from the dark web that reaches their public-facing network, or the traffic leaving their network and heading to the dark web. For security teams, this could mean a vital missed opportunity to catch a threat or evolving attack in progress.

 

There are very few “innocent” reasons for this traffic, making it a very effective indicator that an adversary is encroaching on an organisation’s territory. Beyond sounding the alarm on an immediate incident, it can also provide vital intelligence about early reconnaissance and the malicious tactics that attackers may be attempting to execute. T

 

he faster cyber-security professionals can pinpoint malicious activity, the greater the likelihood of repelling the enemy before an attack can even take shape.

 

Dark web traffic: the threat of reconnaissance

The anonymity offered by the dark web provides cyber-criminals with ideal cover for conducting reconnaissance missions. These missions involve probing networks for vulnerabilities and weak spots, laying the groundwork for more significant cyber-attacks. Detecting such traffic anomalies serves as an effective tripwire for identifying malicious intent and allows organisations to take pre-emptive security measures.

 

Traffic from the dark web to your organisation can be benign, especially if it is to public-facing infrastructure like the website (this could be someone looking at your website via the dark web for privacy reasons). However, when a sudden surge of traffic emanates from the dark web toward your network, especially part of your network that shouldn’t be publicly accessible, it can indicate that adversaries are actively assessing your defences. 

 

By spotting this traffic early, cyber-security professionals can gather critical insights into an attacker’s tactics and objectives. Armed with this information, organisations can adapt their security measures to thwart potential threats before they manifest into full-blown attacks.

 

Signs of malware installation

Unusual or unexpectedly large data flows from the dark web to the corporate network can also be a sign of a malicious actor installing malware.

 

In a real world example from just last year, we helped a European government agency successfully identify and neutralise a cyber-threat, based in part on detecting suspicious dark web traffic early in the attack. Traffic monitoring showed data flowing to the organisation’s servers from the dark web that was much larger than would be expected in comparison to the size of the response. Further investigation uncovered a webshell implemented by a hostile actor within the agency’s network – and this early detection allowed for swift actions, preventing a potential cyber-attack.

 

Traffic to the dark web: insider threats

In the vast majority of organisations, there is no good reason where an employee should be accessing the dark web from the corporate network, and identifying this is a major red flag. Employees browsing the dark web could be exposing their organisations to potential threats such as malware. In more severe cases, this traffic could signify insider threats, where employees intentionally compromise security or engage in illicit activities. 

 

It is crucial that companies identify this outbound traffic, investigate, and shut down the threat. Early detection allows for timely intervention, enabling organisations to reinforce security protocols and avoid potentially catastrophic outcomes.

 

Signs of data exfiltration

Unusual data flow patterns from a corporate network to the dark web is a very clear signal that an attack is underway. Large-scale movement of data in this direction is indicative of data exfiltration: the illicit transfer of sensitive information out of the organisation. Detecting such activities is imperative for preventing data breaches and safeguarding the confidentiality and integrity of an organisation’s valuable data assets.

 

Data breaches can have devastating consequences, including financial losses, damage to reputation, and legal repercussions. Organisations must prioritise the identification of potential data exfiltration attempts. By monitoring dark web traffic for signs of data leakage, cyber-security professionals can take swift action to prevent the loss of critical information and protect their organisation’s interests.

 

Safeguarding against dark web threats

Early detection and rapid response are essential. Dark web traffic, whether directed toward or emanating from a corporate network, can serve as a critical indicator of malicious intent. At present, this is a concerning blind spot for many cyber-security teams, yet it should be as much a part of their overall security hygiene as monitoring their own network.

 

Staying vigilant and informed about the dark web’s potential impact on your network is not just good practice; it’s a necessity. Only by understanding and addressing this hidden facet of cyber-space can organisations hope to safeguard their data, reputation, and future success.

 

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Robert Fitzsimons is Senior Threat Intelligence Engineer at Searchlight Cyber

 

Main image courtesy of iStockPhoto.com