Aviatrix Blog

The Egress Security Gap: How Silk Typhoon and Other Threats Exploit Your Network’s Backdoor

Egress security is critical. Here's how to protect your network from APTs like Silk Typhoon as well as CSP changes.

Egress traffic security has become a critical yet undervalued concern for enterprises operating in the cloud. Recent conversations with IT executives have highlighted increasing risks posed by the evolving threat landscape, cloud service provider (CSP) changes, and network security gaps.

As cloud adoption accelerates, organizations face mounting risks to egress traffic, including:

  • Attacks from advanced persistent threat (APT) groups like Salt Typhoon and Silk Typhoon — Silk Typhoon was recently observed abusing stolen API keys and credentials associated with privileged access management (PAM) systems, cloud application providers, and cloud data management companies, allowing the threat actor to access these companies’ downstream customer environments. APT groups like Silk Typhoon have shown a high level of proficiency in understanding cloud configurations, enabling them to move laterally, establish persistence, and quickly exfiltrate data.
  • CSP changes — At the same time, CSPs like Microsoft Azure are introducing policy changes—such as the upcoming shift in default outbound internet access—that could leave businesses vulnerable if they don’t proactively secure their cloud perimeters.

 

Without robust egress security, enterprises risk data exfiltration, compliance violations, and financial loss. We’re talking millions of dollars due to potential disruption or litigation. Weak egress controls allow attackers to exfiltrate sensitive data undetected, as malicious outbound traffic can blend in with legitimate network activity.

Unprotected outbound traffic can provide attackers with an open door to infiltrate networks, steal data, and disrupt operations. The smartest way to avoid these risks is by securing egress traffic with a cloud-native firewall that delivers deep visibility and control.

 

Why Egress Security Matters More Than Ever

Businesses have long focused on securing inbound threats, but outbound traffic requires just as much scrutiny. Unprotected egress means that bad actors can easily smuggle data out of your network without detection. It can also enable lateral movement—a threat actor enters through one server vulnerability and then accesses other servers. Silk Typhoon, for example, has been known to use common yet effective techniques to move laterally from on-premises environments into cloud environments, where they establish persistence and evade detection.

Many organizations lack full visibility into their egress traffic, leaving them blind to potential threats or costly misconfigurations. As CSPs shift security responsibilities to customers, the risk of data breaches, unauthorized communications, and escalating cloud costs continues to rise.

APT groups like Salt Typhoon and Silk Typhoon exploit vulnerabilities in cloud security, including weak egress controls to establish persistent access and exfiltrate sensitive data. Silk Typhoon in particular has leveraged stolen API credentials to infiltrate multiple customer environments across cloud applications and data platforms.

These sophisticated attackers evade detection by blending in with normal outbound traffic, making visibility and proactive control essential for cloud security. Enterprises that fail to monitor and enforce security policies at their cloud perimeter are at high risk of financial and reputational damage.

 

The Impact of Azure’s Outbound Access Policy Change

Microsoft Azure’s recent policy change on default outbound internet access, which will take effect after September 30, 2025, demonstrates how CSPs are shifting security responsibilities onto customers. After this update, new virtual machines (VMs) will no longer have default internet access. Organizations must actively provision internet access for their VMs. Native options such as Azure NAT gateways may seem like the easiest fix, but they lack comprehensive security. If businesses don’t act proactively to secure their networks, they could find their applications insecurely connecting to the internet with no central visibility, increasing the risk of malware or threat actors exploiting the connection and initiating unauthorized data transfers.

These changes highlight the need for organizations to take control of their cloud security posture rather than depending on CSP defaults. Implementing a robust egress security strategy ensures compliance, mitigates risk, and prevents attackers from taking advantage of network blind spots.

 

The Solution: Cloud-Native Firewalls for Egress Protection

Aviatrix Cloud Firewall provides enterprises with the visibility and control needed to secure egress traffic across multiple cloud environments. Unlike legacy solutions, this cloud-native firewall is designed to operate seamlessly across CSPs, allowing businesses to enforce uniform security policies and prevent unauthorized outbound connections.

With Aviatrix Cloud Firewall, organizations can secure egress traffic by:

  • Monitoring and inspecting outbound traffic in real time to detect anomalies and prevent data exfiltration
  • Enforcing consistent security policies across clouds, avoiding gaps caused by CSP-specific limitations
  • Reducing the risk of costly breaches by proactively blocking malicious outbound connections before they become threats

 

Avoiding Million-Dollar Devastation

Failing to secure egress traffic can lead to devastating financial consequences. A single data breach or compliance violation can cost millions in fines, legal fees, and reputational damage. Protecting your cloud perimeter with a cloud-native firewall is the smartest investment an enterprise can make to ensure security, continuity, and resilience against both cyber threats and CSP-driven disruptions.

As APTs like Salt Typhoon and Silk Typhoon accelerate their attacks on cloud infrastructure, securing egress traffic is no longer optional—it’s essential for safeguarding your business from emerging risks.

 

See how Aviatrix can help you optimize your cloud security from egress traffic to the datacenter edge, all without re-architecting your existing network.