event-generator

event-generator

Generate a variety of suspect actions that are detected by Falco rulesets.

Warning — We strongly recommend that you run the program within Docker (see below), since some commands might alter your system. For example, some actions modify files and directories below /bin, /etc, /dev, etc. Make sure you fully understand what is the purpose of this tool before running any action.

Release notes

Usage

The full command line documentation is here.

List actions

$ event-generator list --all

helper.CombinedServerClient
helper.DoNothing
helper.ExecLs
helper.InboundConnection
helper.NetworkActivity
helper.OutboundConnection
helper.RunShell
k8saudit.ClusterRoleWithPodExecCreated
k8saudit.ClusterRoleWithWildcardCreated
k8saudit.ClusterRoleWithWritePrivilegesCreated
k8saudit.CreateDisallowedPod
k8saudit.CreateHostNetworkPod
k8saudit.CreateModifyConfigmapWithPrivateCredentials
k8saudit.CreateNodePortService
k8saudit.CreatePrivilegedPod
k8saudit.CreateSensitiveMountPod
k8saudit.K8SConfigMapCreated
k8saudit.K8SDeploymentCreated
k8saudit.K8SServiceCreated
k8saudit.K8SServiceaccountCreated
syscall.AddingSshKeysToAuthorizedKeys
syscall.ChangeNamespacePrivilegesViaUnshare
syscall.ChangeThreadNamespace
syscall.ClearLogActivities
syscall.ContactEC2InstanceMetadataServiceFromContainer
syscall.ContainerDriftDetectedChmod
syscall.ContainerDriftDetectedOpenCreate
syscall.CreateFilesBelowDev
syscall.CreateHardlinkOverSensitiveFiles
syscall.CreateHiddenFilesOrDirectories
syscall.CreateSymlinkOverSensitiveFiles
syscall.DbProgramSpawnedProcess
syscall.DebugfsLaunchedInPrivilegedContainer
syscall.DecodingPayloadInContainer
syscall.DeleteOrRenameShellHistory
syscall.DetectCryptoMinersUsingTheStratumProtocol
syscall.DetectReleaseAgentFileContainerEscapes
syscall.DirectoryTraversalMonitoredFileRead
syscall.DisallowedSSHConnectionNonStandardPort
syscall.DropAndExecuteNewBinaryInContainer
syscall.ExecutionFromDevShm
syscall.FilelessExecutionViaMemfdCreate
syscall.FindAwsCredentials
syscall.InterpretedProcsInboundNetworkActivity
syscall.InterpretedProcsOutboundNetworkActivity
syscall.JavaProcessClassFileDownload
syscall.KubernetesClientToolLaunchedInContainer
syscall.LaunchIngressRemoteFileCopyToolsInContainer
syscall.LaunchPackageManagementProcessInContainer
syscall.LaunchRemoteFileCopyToolsInContainer
syscall.LaunchSuspiciousNetworkToolInContainer
syscall.LaunchSuspiciousNetworkToolOnHost
syscall.MkdirBinaryDirs
syscall.ModifyBinaryDirs
syscall.ModifyContainerEntrypoint
syscall.ModifyShellConfigurationFile
syscall.MountLaunchedInPrivilegedContainer
syscall.NetcatRemoteCodeExecutionInContainer
syscall.NonSudoSetuid
syscall.PacketSocketCreatedInContainer
syscall.PolkitLocalPrivilegeEscalationVulnerabilityCVE20214034
syscall.PotentialLocalPrivilegeEscalationViaEnvironmentVariablesMisuse
syscall.ProgramRunWithDisallowedHttpProxyEnv
syscall.PtraceAntiDebugAttempt
syscall.PtraceAttachedToProcess
syscall.ReadEnvironmentVariableFromProcFiles
syscall.ReadSensitiveFileTrustedAfterStartup
syscall.ReadSensitiveFileUntrusted
syscall.ReadShellConfigurationFile
syscall.ReadSshInformation
syscall.RemoveBulkDataFromDisk
syscall.RunShellUntrusted
syscall.ScheduleCronJobs
syscall.SearchPrivateKeysOrPasswords
syscall.SetSetuidOrSetgidBit
syscall.SudoPotentialPrivilegeEscalation
syscall.SystemProcsNetworkActivity
syscall.SystemUserInteractive
syscall.UnexpectedUDPTraffic
syscall.UnprivilegedDelegationOfPageFaultsHandlingToAUserspaceProcess
syscall.UserMgmtBinaries
syscall.WriteBelowBinaryDir
syscall.WriteBelowEtc
syscall.WriteBelowMonitoredDir
syscall.WriteBelowRoot
syscall.WriteBelowRpmDatabase

Run actions

event-generator run [regexp]

Without arguments, it runs all actions; otherwise, only those actions match the given regular expression.

For example, to run only those actions containing the word Files in their name:

$ sudo event-generator run syscall\.\*Files\.\*

INFO sleep for 100ms                               action=syscall.ReadSensitiveFileUntrusted
INFO action executed                               action=syscall.ReadSensitiveFileUntrusted
INFO sleep for 100ms                               action=syscall.CreateSymlinkOverSensitiveFiles
INFO action executed                               action=syscall.CreateSymlinkOverSensitiveFiles
INFO sleep for 100ms                               action=syscall.DirectoryTraversalMonitoredFileRead
INFO action executed                               action=syscall.DirectoryTraversalMonitoredFileRead
INFO sleep for 100ms                               action=syscall.ReadSensitiveFileTrustedAfterStartup
INFO spawn as "httpd"                              action=syscall.ReadSensitiveFileTrustedAfterStartup args="^syscall.ReadSensitiveFileUntrusted$ --sleep 6s"
INFO sleep for 6s                                  action=syscall.ReadSensitiveFileUntrusted as=httpd
INFO action executed                               action=syscall.ReadSensitiveFileUntrusted as=httpd

Useful options:

• --loop to run actions in a loop
• --sleep to set the length of time to wait before running an action (default to 100ms)

Also, note that not all actions are enabled by default. To run all actions, use the --all option.

Further options are documented here.

With Docker

Run all events with the Docker image locally:

docker run -it --rm falcosecurity/event-generator run

With Kubernetes

It can be deployed in a Kubernetes cluster using the event-generator helm chart. Before installing the chart, add the falcosecurity charts repository:

helm repo add falcosecurity https://falcosecurity.github.io/charts
helm repo update

Run all events once using a Kubernetes job:

helm install event-generator falcosecurity/event-generator \
  --namespace event-generator \
  --create-namespace \
  --set config.loop=false \
  --set config.actions=""

Run all events in a loop using a Kubernetes deployment:

helm install event-generator falcosecurity/event-generator \
  --namespace event-generator \
  --create-namespace \
  --set config.actions=""

N.B. The above commands apply to the event-generator namespace. Use a different name to use a different namespace. It will generate events in the same namespace.

Collections

Generate System Call activity

The syscall collection performs a variety of suspect actions detected by the default Falco ruleset.

Note that only actions for stable rules are enabled by default. To enable all other actions, use the --all option.

$ docker run -it --rm falcosecurity/event-generator run syscall --loop

The above command loops forever, incessantly generating a sample event every 100 miliseconds.

Generate activity for the k8saudit rules

The k8saudit events collection in the event-generator is maintained on a best-effort basis and may not fully work.

The k8saudit collection generates activity that matches the k8s audit event ruleset.

Note that all k8saudit are disabled by default. To enable them, use the --all option.

$ event-generator run k8saudit --all --loop --namespace `falco-eg-sandbox`

N.B.: the namespace must exist already.

The above command loops forever, creating resources in the falco-eg-sandbox namespace and deleting the after each iteration.

N.B.

• the namespace must already exist
• to produce any effect the Kubernetes audit log must be enabled, see here

Test rules

Since v0.4.0, this tool introduces a convenient integration test suite for Falco rules. The event-generator test command can run actions and test them against a running Falco instance.

This feature requires Falco 0.24.0 or newer. Before using the command below, you need Falco installed and running with the gRPC Output enabled.

Test locally (syscall only)

Run the following command to test syscall actions on a local Falco instance (connects via Unix socket to /run/falco/falco.sock by default):

sudo ./event-generator test syscall

Test on Kubernetes

Before running the following commands make sure you have added the falcosecurity charts repository as explained here.

Test all events once using a Kubernetes job:

helm install event-generator falcosecurity/event-generator \
  --namespace event-generator \
  --create-namespace \
  --set config.command=test \
  --set config.loop=false \
  --set config.actions=""

Test all events in a loop using a Kubernetes deployment:

helm install event-generator falcosecurity/event-generator \
  --namespace event-generator \
  --create-namespace \
  --set config.command=test \
  --set config.actions=""

Note that to test k8saudit events, you need Kubernetes Audit Log functionality enabled in Kubernetes and the k8saudit plugin in Falco.

Benchmark

Since v0.5.0, the event-generator can also be used for benchmarking a running instance of Falco. The command event-generator bench generates a high number of Event Per Second (EPS) to show you events throughput allowed by your Falco installation.

Be aware that before Falco 0.37 a rate-limiter for notifications that affects the gRPC Outputs APIs was present. You probably need to increase the outputs.rate and outputs.max_burst values within the Falco configuration, otherwise EPS will be rate-limited by the throttling mechanism.

Run a benchmark

Before starting a benchmark, the most important thing to understand is that the --sleep option controls the number of EPS (default to 250ms): reducing this value will increase the EPS. Furthermore, if the --loop option is set, the sleeping duration is automatically halved on each round. The --pid option can be used to monitor the Falco process.

You can find more details about the command-line usage here.

Please, keep in mind that not all actions can be used for benchmarking since some of them take too long to generate a high number of EPS. For example, k8saudit actions are not supposed to work, since those actions need some time to create Kubernetes resources. Also, some syscall actions sleep for a while (like the syscall.ReadSensitiveFileUntrusted) thus cannot be used.

Benchmark example

A common way for benchmarking a local Falco instance is by running the following command (that connects via Unix socket to /run/falco/falco.sock by default):

sudo event-generator bench "ChangeThreadNamespace|ReadSensitiveFileUntrusted" --all --loop --sleep 10ms --pid $(pidof -s falco)

📣 New suite command

Since v0.13, the event-generator ships a new top-level suite command that consumes test scenarios described in YAML files. While the traditional run, test and bench sub-commands execute actions coded in Go, the new suite sub-commands consume YAML descriptions, so a new scenario can be added without writing any Go code.

Tests are grouped into test suites by the Falco rule they target, and reports are emitted per suite. Three sub-commands are available:

• event-generator suite run performs the actions declared in the description, without verifying any outcome.
• event-generator suite test performs the same actions and verifies that the running Falco instance produced the expected alerts.
• event-generator suite explain documents the YAML description language by following the property hierarchies in the schema.

The example below exercises a containerised process chain, a clientServer resource, a step that binds to a value exposed by the resource, an expected Falco outcome and template cases that expand into multiple concrete tests:

tests:
  - name: "Drop and execute new binary in container"
    rule: "Drop and execute new binary in container"
    description: "Testing reverse shell rule"
    runner: HostRunner
    context:
      container:
        image: image-name
        name: container-name
      processes:
        - args: "arg1 arg2"
          name: "proc0"
          exe: "arg0"
          user: user1
        - user: user2
        - user: root
          capabilities: "cap_net_admin,cap_net_bind_service,cap_chown=ep"
    resources:
      - type: clientServer
        name: cs1
        l4Proto: "%{item.l4Proto}"
        address: "%{item.address}"
    steps:
      - type: syscall
        name: d1
        syscall: dup2
        args:
          oldFd: "${cs1.client.fd}"
          newFd: 0
    expectedOutcome:
      source: "syscall"
    cases:
      - strategy: matrix
        values:
          l4Proto: ["tcp4", "udp4"]
          address: ["11.0.0.1:80"]
      - strategy: vector
        values:
          l4Proto: "unix"
          address: ""

The full YAML language is documented in the YAML description reference. Working examples covering each feature are available under samples/.

FAQ

What sample events can this tool generate?

See the events registry.

Can I contribute by adding new events?

Sure!

Check out the events registry conventions, then feel free to open a PR!

Your contribution is highly appreciated.

Can I use this project as a library?

This project provides three main packages that can be imported and used separately:

• /cmd contains the CLI implementation
• /events contains the events registry
• /pkg/runner contains the actions runner implementations

Feel free to use them as you like on your projects.

Acknowledgments

Special thanks to Mark Stemm (@mstemm) — the author of the first event generator.