Security operations maintain and restores the security assurances of the system as live adversaries attack it. The tasks of security operations are described well by the NIST Cybersecurity Framework functions of Detect, Respond, and Recover.
Detect - Security operations must detect the presence of adversaries in the system, who are incented to stay hidden in most cases as this allows them to achieve their objectives unimpeded. This can take the form of reacting to an alert of suspicious activity or proactively hunting for anomalous events in the enterprise activity logs.
Respond – Upon detection of potential adversary action or campaign, security operations must rapidly investigate to identify whether it is an actual attack (true positive) or a false alarm (false positive) and then enumerate the scope and goal of the adversary operation.
Recover – The ultimate goal of security operations is to preserve or restore the security assurances (confidentiality, integrity, availability) of business services during and after an attack.
The most significant security risk most organizations face is from human attack operators (of varying skill levels). This is because risk from automated/repeated attacks have been mitigated significantly for most organizations by signature and machine learning based approaches built into anti-malware (though there are notable exceptions like Wannacrypt and NotPetya, which moved faster than these defenses).
While human attack operators are challenging to face because of their adaptability (vs. automated/repeated logic), they are operating at the same “human speed” as defenders, which help level the playing field.
Security Operations (sometimes referred to as a Security Operations Center (SOC)) has a critical role to play in limiting the time and access an attacker can get to valuable systems and data. Each minute that an attacker has in the environment allows them to continue to conduct attack operations and access sensitive/valuable systems.
Objective and metrics
The metrics you measure will have a significant effect on the behaviors and outcomes of security operations. Focusing on the right measurements will help drive continuous improvement in the right areas that meaningfully reduce risk.
To ensure that security operations are effectively containing attackers access, the objectives should focus on
Reducing time to acknowledge an alert to ensure that detected adversaries are not ignored while defenders are spending time investigating false positives.
Reducing time to remediate a discovered adversary to reduce their opportunity time to conduct and attack and reach sensitive systems
Prioritizing security investments into systems that have high intrinsic value (likely targets / high business impact) and access to many systems or sensitive systems (administrator accounts and sensitive users)
Increase focus on proactively hunting for adversaries as your program matures and reactive incidents get under control. This is focused on reducing the time that a higher skilled adversary can operate in the environment (for example, skilled enough to evade reactive alerts).
For more information on how Microsoft’s SOC uses these metrics, see https://aka.ms/ITSOC.
Hybrid enterprise view
Security operations should ensure their tooling, processes, and analyst skillsets enable visibility across the full span of their hybrid estate.
Attackers don’t restrict their actions to a particular environment when targeting an organization, they will attack resources on any platform using any method available. Enterprise organizations adopting cloud services like Azure and AWS are effectively operating a hybrid of cloud and on-premises assets.
Security operations tooling and processes should be designed for attacks on cloud and on-premises assets as well as attackers pivoting between cloud and on-premises resources using identity or other means. This enterprise-wide view will enable security operations teams to rapidly detect, respond, and recover from attacks, reducing organizational risk.
Leverage native detections and controls
You should favor the use of security detections and controls built into the cloud platform before creating custom detections using event logs from the cloud.
Cloud platforms evolve rapidly with new features, which can make maintaining detections challenging. Native controls are maintained by the cloud provider and are typically high quality (low false positive rate).
Because many organizations may use multiple cloud platforms and need a unified view across the enterprise, you should ensure these native detections and controls feed a centralize SIEM or other tool. We don’t recommend trying to substitute generalized log analysis tools and queries instead of native detections and controls. These tools can offer numerous values for proactive hunting activities, but getting to a high-quality alert with these tools requires application of deep expertise and time that could be better spent on hunting and other activities.
To complement the broad visibility of a centralized SIEM (like Azure Sentinel, Splunk, or QRadar), you should leverage native detections and controls such as
Organizations using Azure should leverage capabilities like Azure Security Center for alert generation on the Azure platform.
Organizations should leverage native logging capabilities like Azure Monitor and AWS CloudTrail for pulling logs into a central view
Organizations using Azure should leverage Network Security Group (NSG) capabilities for visibility into network activities on the Azure platform.
Investigation practices should leverage native tools with deep knowledge of the asset type such as an Endpoint Detection and Response (EDR) solution, Identity tools, and Azure Sentinel.
Prioritize alert and log integration
Ensure that you are integrating critical security alerts and logs into SIEMs without introducing a high volume of low value data.
Introducing too much low value data can increase SIEM cost, increase noise and false positives, and lower performance.
The data you collect should be focused on supporting one or more of these operations activities:
Alerts (detections from existing tools or data required for generating custom alerts)
Investigation of an incident (for example, required for common queries)
Proactive hunting activities
Integrating more data can allow you to enrich alerts with additional context that enable rapid response and remediation (filter false positives, and elevate true positives, etc.), but collection is not detection. If you don’t have a reasonable expectation that the data will provide value (for example, high volume of firewall denies events), you may deprioritize integration of these events.