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Modern Attack Surfaces

Walk the lifecycle › Development A: Technical feasibility › Going deeper

The lifecycle in this framework applies to any environment. The assumptions that most detection programs carry do not. Many were formed when the estate consisted of Windows endpoints on a corporate network, and they transfer poorly to environments where the endpoint is not the point of compromise.

This deep dive belongs to the technical feasibility phase because the first question it changes is what can be observed. Each section describes, for one kind of environment, which assumptions no longer hold, where the most valuable detection opportunities lie, and what that means for applying the framework.

Running example. The consent phishing detection is an identity detection. It involves no endpoint and no malware, and the attacker's access survives a password reset. The identity section below explains why this pattern has become common.

The environments covered are identity, the cloud control plane, SaaS applications, containers and Kubernetes, CI/CD and the software supply chain, operational technology, and AI and machine learning systems.


Identity

Identity is the primary attack surface. In most intrusions that matter, no malware executes and no endpoint is compromised.

What changes

Assumption Reality
Compromise begins at an endpoint Compromise begins at an identity provider, frequently from an unmanaged device
Authentication is the control point Post-authentication authorization is the control point; tokens and consent grants outlive credentials
Password reset contains the incident Password reset does nothing to a stolen refresh token, a consented application, or an added authentication method
MFA is a detection boundary MFA fatigue, adversary-in-the-middle proxies and device-code phishing all produce successful, MFA-satisfied sign-ins

Priority detection surfaces

Surface Why
OAuth consent and permission grants Persistent delegated access that survives credential rotation. See the worked example
Authentication method registration Adding a method is the quietest persistence mechanism in most tenants
Conditional access policy modification Disabling a control is a precondition to using it
Privileged role assignment and eligible-role activation Privilege escalation in a cloud directory
Token anomalies Impossible travel is weak; token replay from a new device or unexpected client ID is strong
Federation and trust changes Adding a federated domain or signing certificate is total tenant compromise
Service principal credential addition A new secret on an existing application is backdoor persistence with legitimate-looking telemetry

Framework implications

  • Asset criticality in the planning rubric applies to identities, not only systems. A privileged identity is a tier 1 asset.
  • Response playbooks MUST include token revocation explicitly. Consent removal or password reset alone does not end access, and this step is the one most often omitted.
  • Robustness: identity telemetry is comparatively stable and schema-consistent, so behavioral detections here tend to last longer than endpoint equivalents.

Cloud control plane

What changes

The control plane is an API. Compromise is a sequence of authorized API calls, each individually legitimate. There is no malicious binary to find.

Assumption Reality
Lateral movement is network-based Lateral movement is role assumption and cross-account trust
Persistence is a file or service Persistence is an IAM role, a Lambda trigger, an automation account or a resource policy
Exfiltration crosses the perimeter Exfiltration is a bucket policy change or a snapshot shared to an external account
The blast radius is the host The blast radius is whatever the compromised principal may call

Priority detection surfaces

Surface Why
IAM policy and role changes Privilege escalation, and the precondition to nearly everything else
Resource sharing to external accounts Snapshot, image and bucket sharing is quiet, complete exfiltration
Logging and guardrail modification Disabling CloudTrail, audit logs or a security service precedes the rest
Credential and key creation New access keys on an existing principal
Serverless function and automation changes Execution-on-trigger persistence
Unusual regions Activity in never-used regions is a durable, high-precision signal

Framework implications

  • Telemetry is cheap and complete relative to endpoint. TEL-3 inventory work is comparatively easy here; the difficulty is volume and cost.
  • Many control-plane detections are invariant tier: the API call is the technique. This is the highest-yield robustness territory available.
  • Preventive controls (service control policies, guardrails) are strong here, which changes the coverage_gap score. Monitor the guardrail itself.

SaaS

The estate most programs monitor least. Data lives in applications the security team does not administer and frequently cannot query.

Surface Why
Third-party application integration The most common SaaS-to-SaaS lateral path
Sharing and permission changes Public link creation, external collaborator addition
Administrative action outside change windows Small admin populations make anomalies visible
Bulk export and download The clearest exfiltration signal available in most SaaS platforms
Authentication bypass Legacy protocols, app passwords, and API tokens that skip conditional access

The dominant constraint is telemetry availability. Many SaaS platforms emit audit logs only at premium licence tiers or with short retention. Make this a procurement requirement: audit log availability, retention and API access belong in the security requirements for any SaaS purchase. Raising it after signature is raising it too late, and FEA-1 will otherwise block the use case permanently.


Containers and Kubernetes

Surface Why
Workload spawning an interactive shell Containers are normally single-purpose; a shell is anomalous by construction
Privileged or host-namespace containers The standard escape path
Service account token abuse Kubernetes credentials are files in the filesystem
API server anomalies exec, port-forward, secret enumeration
Unexpected image sources Registry outside the approved set
Runtime drift from the image A process running that was not in the image

The advantage here is that container environments are more predictable than general-purpose hosts. Immutability makes deviation detectable. Detections built on "this workload should never do X" are often invariant tier and exceptionally precise.

The disadvantage is ephemerality: a container may live for seconds. Telemetry must be streamed and correlated by workload identity, not host.


CI/CD and software supply chain

The highest-leverage target in most organizations, and the least monitored. Build systems hold production credentials, run arbitrary code by design, and are trusted by everything downstream.

Surface Why
Pipeline definition changes A modified workflow file is arbitrary code execution with production credentials
Secret access anomalies A job reading secrets it has never read before
Self-hosted runner compromise Long-lived, credential-rich, rarely monitored
Dependency changes Typosquats, newly introduced transitive dependencies, maintainer changes
Artifact signing failures Unsigned or mis-signed artifacts reaching a registry
Branch protection modification Disabling review is the precondition to injecting code

Framework implication. The detection repository described in Detection as Code is itself in this category. A program that automates detection deployment has created a new high-value target and MUST monitor it. Apply the framework to itself.


Operational technology

Where the framework applies with the most modification.

Difference Consequence
Availability outranks confidentiality Automated containment is usually forbidden. RSP-3 pre-authorisation is typically "none"
Protocols are deterministic Baselining works unusually well; deviation is meaningful
Systems cannot be patched or instrumented Detection is almost entirely network-based and passive
Change is rare and scheduled Any unscheduled change is high-signal
Safety consequences are physical Response playbooks must involve engineering and safety authorities, not only IT

Use the same lifecycle. Change the response engineering assumptions: RSP-3 authority, escalation paths and containment options all differ fundamentally.


AI and machine learning systems

New surface, and the one most likely to date this framework if omitted. Map threats using MITRE ATLAS alongside ATT&CK; the detection schema supports atlas_techniques for this purpose.

Two distinct problems

1. Attacks on AI systems the organization operates.

Surface Why
Prompt injection reaching a tool-enabled agent Indirect injection via retrieved content is the dominant practical attack
Agent tool invocation anomalies An agent calling tools or APIs outside its expected pattern
Model or system prompt extraction Repeated probing; unusual output volume
Training and RAG data poisoning Unauthorized writes to a corpus or vector store
Model artifact tampering Changes to weights or model files outside the deployment pipeline
Inference cost anomalies Resource abuse; also an early indicator of automated probing

The critical framing: an AI agent with tool access is a privileged identity. It authenticates, it holds permissions, and it acts. Treat it as one. Give it an identity in the asset inventory, score it in the planning rubric, monitor its authorization changes and its actions, and give it a containment procedure. Most organizations currently do none of this.

2. Attacks that use AI.

Adversaries using generative tooling produce higher-quality lures and faster tooling iteration. This does not create new techniques so much as it degrades detections that relied on poor adversary craft. Detections whose implicit signal was "badly written English" or "unusual binary structure" have lost efficacy and should be re-scored for robustness.

Framework implications

  • Add AI systems to the telemetry inventory (TEL-3). Most have none today.
  • Agent action logs are a required log source for any agent with write access.
  • Expect this section to change faster than any other. It is versioned with the specification for that reason.

Applying the framework across surfaces

The lifecycle does not change. What changes per surface is:

Element What to re-examine
Asset criticality The unit of value: identity, workload, dataset, pipeline, agent
Telemetry availability Frequently the binding constraint; sometimes a procurement problem
Robustness API-based surfaces offer more invariant detections than endpoints
Response authority OT and production cloud constrain automated containment
Review cadence Faster-changing surfaces need shorter cadences

The lifecycle itself is the same in every environment. A consent grant, a container escape, an IAM policy change and an agent tool invocation each need a business driver, a hypothesis, telemetry, logic, a test, a response and a review date.


In brief

  • Identity is now the primary attack surface. Many significant intrusions involve no malware and no endpoint compromise.
  • Cloud control planes, SaaS applications and pipelines are attacked through sequences of authorized API calls, which demand different detection logic from endpoint work.
  • Telemetry availability is often the binding constraint, particularly for SaaS, and is best addressed at procurement.
  • AI agents with tool access are best treated as privileged identities, with their own inventory entry, monitoring and containment procedure.

What comes next

With feasibility established, the lifecycle moves to the detection engineering phase: turning confirmed telemetry into detection logic that states its intent, handles exceptions, and is tested before release.