By understanding threat actor behavior, organizations can effectively prioritize security efforts to disrupt attack paths and protect critical systems and assets. Analysis of the events for this report found that many are readily mitigated by patching legacy vulnerabilities and addressing misconfigurations to help limit attack paths. Additional findings include:

• Ransomware had a monumental impact on organizations in 2021, responsible for approximately 38% of all breaches. 
• 6% of breaches were the result of unsecured cloud databases. 
• Unpatched SSL VPNs continue to provide an ideal entry point for attackers to perform cyberespionage, exfiltrate sensitive and proprietary information as well as encrypt networks.
• Threat groups, particularly ransomware, have increasingly exploited vulnerabilities and misconfigurations in Active Directory.
• Software libraries and network stacks used commonly amongst OT devices often introduce additional risk when security controls and code audits are not in place.
• Ransomware groups favored physical supply chain disruption as a tactic to extort payment while cyberespionage campaigns exploited the software supply chain to access sensitive data.
• Healthcare and education experienced the greatest disruption from data breaches.

“Migration to cloud platforms, reliance on managed service providers, software and infrastructure as a service have all changed how organizations must think about and secure the perimeter,” explains Claire Tills, Senior Research Engineer, Tenable. “Modern security leaders and practitioners must think more holistically about the attack paths that exist within their networks and how they can efficiently disrupt them. By examining threat actor behavior we can understand which attack paths are the most fruitful and leverage these insights to define an effective security strategy. ”

Staying on top of patching assets is difficult enough given the sheer volume of disclosed vulnerabilities, but in 2021 it was even more challenging due to incomplete patches, miscommunications from vendors and patch bypasses. In 2021, there were 21,957 common vulnerabilities and exposures (CVEs) reported, representing a 19.6% increase over the 18,358 reported in 2020 and a 241% increase over the 6,447 disclosed in 2016. From 2016 to 2021 the number of CVEs increased at an average annual percentage growth rate of 28.3%.

The full report is available for download, and includes key stats and nine top takeaways.