Browse Rules

Rare GCP Audit Failure Event Code

A machine learning job detected an unusual failure in a GCP Audit message. These can be byproducts of attempted or successful persistence, privilege escalation, defense evasion, discovery, lateral movement, or collection.

Spike in GCP Audit Failed Messages

A machine learning job detected a significant spike in the rate of a particular failure in the GCP Audit messages. Spikes in failed messages may accompany attempts at privilege escalation, lateral movement, or discovery.

Unusual City For a GCP Event

A machine learning job detected GCP Audit event activity that, while not inherently suspicious or abnormal, is sourcing from a geolocation (city) that is unusual for the event action. This can be the result of compromised credentials or keys being used by a threat actor in a different geography than the authorized user(s).

Unusual Country For a GCP Event

A machine learning job detected GCP Audit event activity that, while not inherently suspicious or abnormal, is sourcing from a geolocation (country) that is unusual for the event action. This can be the result of compromised credentials or keys being used by a threat actor in a different geography than the authorized user(s).

Unusual GCP Event for a User

A machine learning job detected an GCP Audit event that, while not inherently suspicious or abnormal, is being made by a user context that does not normally use the event action. This can be the result of compromised credentials or keys as someone uses a valid account to persist, move laterally, or exfiltrate data.

GCP Logging Sink Deletion

Identifies a Logging sink deletion in Google Cloud Platform (GCP). Every time a log entry arrives, Logging compares the log entry to the sinks in that resource. Each sink whose filter matches the log entry writes a copy of the log entry to the sink's export destination. An adversary may delete a Logging sink to evade detection.

GCP Logging Sink Modification

Identifies a modification to a Logging sink in Google Cloud Platform (GCP). Logging compares the log entry to the sinks in that resource. Each sink whose filter matches the log entry writes a copy of the log entry to the sink's export destination. An adversary may update a Logging sink to exfiltrate logs to a different export destination.

GCP Pub/Sub Topic Creation

Identifies the creation of a topic in Google Cloud Platform (GCP). In GCP, the publisher-subscriber relationship (Pub/Sub) is an asynchronous messaging service that decouples event-producing and event-processing services. A topic is used to forward messages from publishers to subscribers.

GCP Pub/Sub Subscription Creation

Identifies the creation of a subscription in Google Cloud Platform (GCP). In GCP, the publisher-subscriber relationship (Pub/Sub) is an asynchronous messaging service that decouples event-producing and event-processing services. A subscription is a named resource representing the stream of messages to be delivered to the subscribing application.

GCP Pub/Sub Subscription Deletion

Identifies the deletion of a subscription in Google Cloud Platform (GCP). In GCP, the publisher-subscriber relationship (Pub/Sub) is an asynchronous messaging service that decouples event-producing and event-processing services. A subscription is a named resource representing the stream of messages to be delivered to the subscribing application.

GCP Logging Bucket Deletion

Identifies a Logging bucket deletion in Google Cloud Platform (GCP). Log buckets are containers that store and organize log data. A deleted bucket stays in a pending state for 7 days, and Logging continues to route logs to the bucket during that time. To stop routing logs to a deleted bucket, you can delete the log sinks that have the bucket as their destination, or modify the filter for the sinks to stop it from routing logs to the deleted bucket. An adversary may delete a log bucket to evade d

GCP Secret Manager ListSecrets Across Multiple Projects

Detects a single identity listing Google Cloud Secret Manager secrets across many distinct projects in a short window. ListSecrets does not return secret values, but sweeping many projects is a common reconnaissance step before targeted AccessSecretVersion calls. Legitimate workloads typically list secrets within one project or a small set of projects; cross-project bursts from one user and source IP are uncommon outside security tooling or compromise.

GCP IAM Service Account Impersonation Role Granted

Identifies when a service account impersonation role is granted on a Google Cloud Platform (GCP) service account via a SetIamPolicy operation. Roles such as "roles/iam.serviceAccountTokenCreator", "roles/iam.serviceAccountUser", and "roles/iam.serviceAccountOpenIdTokenCreator" allow a principal to mint access or identity tokens for the target service account, or to act as it when deploying resources. Adversaries who have obtained sufficient privileges may grant themselves or an attacker-controll

GCP Pub/Sub Topic Deletion

Identifies the deletion of a topic in Google Cloud Platform (GCP). In GCP, the publisher-subscriber relationship (Pub/Sub) is an asynchronous messaging service that decouples event-producing and event-processing services. A publisher application creates and sends messages to a topic. Deleting a topic can interrupt message flow in the Pub/Sub pipeline.

GKE Pod Exec with Curl or Wget to HTTPS

Detects successful GKE pod exec sessions where the executed command implies curl or wget fetching an HTTPS URL. Attackers with pods/exec often run one-liners to stage tooling, pull scripts or binaries, or exfiltrate data over HTTPS—activity that should be rare compared to shells, debuggers, or expected health checks. Common cluster health, localhost, and OIDC/JWKS endpoint patterns are excluded to reduce benign automation noise. GKE records the command in gcp.audit.labels.command.gke.io/command

GKE Sensitive RBAC Change Followed by Workload Modification

Detects when the same GKE identity creates or modifies a Role or ClusterRole with high-risk permissions (wildcard access, RBAC escalation verbs, or access to secrets / privileged APIs) and also creates or patches a DaemonSet, Deployment, or CronJob within five minutes. This correlation is consistent with RBAC-based privilege escalation followed by payload deployment.

GKE Certificate Signing Request Self-Approved

Detects when the same non-system GKE identity creates a CertificateSigningRequest (CSR) and then approves that same CSR within five minutes, consistent with self-approval abuse. Attackers who gain CSR create and approval RBAC can submit a certificate request and approve it themselves to obtain a long-lived client certificate without involving cluster operators, a pattern documented in Kubernetes persistence research and adversary emulation.

GKE Client Certificate Signing Request Created or Approved

Detects creation or approval of a GKE CertificateSigningRequest (CSR) by a non-system identity. This is a breadth baseline rule for human or custom automation CSR activity on GKE. Attackers with cluster access can submit and approve CSRs to obtain long-lived client certificates that survive token revocation and RBAC changes. Use companion rules to evaluate signer choice, requested identity, and self-approval behavior.

GKE Anonymous Endpoint Permission Enumeration

Detects bursts of GKE API requests from an anonymous identity that probe many distinct actions and resources with mostly failed outcomes. This pattern is consistent with unauthenticated permission enumeration against an exposed API server. On GKE GCP audit logs, unauthenticated probes often omit "client.user.email" (null principal) with Unauthorized failures; those events are included alongside "system:anonymous" / "system:unauthenticated".

GKE Certificate Signing Request API Client Signer Requested

Detects creation of a GKE CertificateSigningRequest (CSR) that requests the kubernetes.io/kube-apiserver-client signer. This signer issues general API client certificates with few subject restrictions, unlike the restricted kubelet signers used for node certificate rotation. Attackers with CSR permissions use this signer to mint long-lived credentials for privileged identities such as system:kube-controller-manager, enabling persistence and privilege escalation that survives token revocation and

GKE Pod Exec Potential Reverse Shell

Detects successful GKE pod exec sessions whose command resembles reverse-shell or bind-shell one-liner patterns, including /dev/tcp and /dev/udp redirection, netcat/ncat exec-style flags, socat shell handoff, mkfifo pipelines, and common language socket idioms. Legitimate debug sessions sometimes use similar building blocks, but together these patterns align with post-exploitation interactive access and command-and-control. Common localhost /dev/tcp health-check ports are excluded. GKE records t

GKE Pod Exec Sensitive File or Credential Path Access

Detects successful GKE pod exec sessions where the executed command references high-value host or in-cluster paths: mounted service account or platform tokens, kubelet and control-plane configuration areas, host identity stores, root or home credential directories, common private-key and keystore extensions, process environment dumps, and configuration filenames suggestive of embedded secrets. Attackers with pods/exec often use these one-liners to steal credentials before lateral movement or pri

GKE Certificate Signing Request for Privileged Identity

Detects creation of a GKE CertificateSigningRequest (CSR) whose decoded subject requests a highly privileged Kubernetes identity in the Common Name (CN), such as system:masters, system:kube-controller-manager, or system:admin. This rule is scoped to identities with cluster-admin-equivalent or control-plane impersonation value. Attackers who can create and approve CSRs can use this technique to clone credentials for powerful identities and obtain durable cluster access. This signal applies to any

GKE Pod Exec Cloud Instance Metadata Access

Detects successful GKE pod exec sessions whose command references Google Cloud instance metadata endpoints, including metadata.google.internal, computeMetadata/v1, or the link-local metadata IP 169.254.169.254. Workloads that reach the GKE metadata service from an exec session are often attempting to harvest short-lived credentials or instance attributes from the node or workload identity boundary. That behavior is high risk because it can expose cloud credentials to code running inside a contai

Azure AD Graph Access with Unusual User and ASN

Identifies Azure AD Graph (graph.windows.net) requests originating from network sources outside the major public-cloud and Microsoft ASNs that legitimate first-party callers normally come from. Adversary tooling typically rides on commodity hosting (residential ISPs, VPS providers, anonymisers) which produces an ASN distribution very different from the Microsoft / AWS / GCP / Akamai / Cloudflare ranges that dominate legitimate AAD Graph traffic.