Hackers Built Malware to Steal Cisco Traffic Keys

Hackers used a critical Cisco flaw to install custom malware that steals the encryption keys protecting your network traffic.

Attackers exploited a critical vulnerability in Cisco’s Catalyst SD-WAN platform to install custom malware designed to steal network encryption keys, according to a report from Cisco Talos. The flaw, which Cisco patched in February, allowed hackers to gain deep access to the systems that manage an organization's wide-area network. The security researchers discovered a piece of malware they named KeyDrift, which was specifically built to copy the keys that encrypt traffic flowing between a company’s different sites. Cisco described the attacks as “historical” but did not specify when they occurred, leaving a window of uncertainty for customers about when their networks may have been exposed. The attackers’ goal was not to disrupt networks but to silently collect the tools needed to decrypt sensitive internal communications.

The attack represents a sophisticated approach to corporate espionage. Instead of directly stealing data, the KeyDrift malware targets the security mechanism itself. SD-WAN technology relies on strong encryption to create secure, private tunnels for data traveling over public internet connections. By stealing the encryption keys, attackers can potentially decrypt any captured network traffic, past or present, that was protected by those keys. The malware was designed to copy these keys and store them for later retrieval. This method is patient and stealthy, suggesting the work of an advanced adversary focused on long-term intelligence gathering rather than a quick financial payout. It turns the core security feature of SD-WAN into a liability, allowing attackers to read sensitive data as if it were sent in plain text.

This incident fits into a broader trend of attackers targeting core network infrastructure. Devices like routers, firewalls, and VPN concentrators are high-value targets because they sit at the crossroads of all network traffic. Compromising one of these systems provides a powerful vantage point for surveillance and deeper network intrusion. Similar campaigns have targeted infrastructure from other major vendors, showing that no single provider is immune. The development of custom malware like KeyDrift, tailored for a specific device and purpose, indicates a well-resourced and determined threat actor. These are not opportunistic attacks using off-the-shelf tools; they are targeted operations designed to bypass the primary defenses of enterprise networks.

The key takeaway for security and IT teams is that patching a vulnerability is only the first step. Because the exploitation happened before the fix was available, organizations must now shift their focus to threat hunting. Teams managing Cisco SD-WAN deployments need to actively search for signs of historical compromise, such as the presence of the KeyDrift malware or other unauthorized activity. This incident underscores the critical need for robust monitoring, logging, and anomaly detection on all network management systems. Looking ahead, security professionals should anticipate that attackers will continue to target the management plane of critical infrastructure, forcing a greater emphasis on securing the systems that control the network, not just the data that flows through it.

This attack undermines the fundamental security of SD-WAN by targeting the encryption keys themselves. For security and network teams, it shows that even patched systems may have been compromised historically, potentially allowing attackers to decrypt captured traffic and access sensitive internal communications.

A compromise of traffic encryption keys exposes a company's most sensitive internal data, from financial records to intellectual property. This creates immense risk for data breaches, regulatory fines, and loss of customer trust. Investigating such a deep-level compromise requires significant security resources.