LoFP LoFP / automated configuration management or monitoring scripts that use lolbins via ssm for legitimate purposes. consider excluding known automation accounts or specific command patterns.

Techniques

Sample rules

AWS EC2 LOLBin Execution via SSM SendCommand

Description

Identifies the execution of Living Off the Land Binaries (LOLBins) or GTFOBins on EC2 instances via AWS Systems Manager (SSM) SendCommand API. This detection correlates AWS CloudTrail SendCommand events with endpoint process execution by matching SSM command IDs. While AWS redacts command parameters in CloudTrail logs, this correlation technique reveals the actual commands executed on EC2 instances. Adversaries may abuse SSM to execute malicious commands remotely without requiring SSH or RDP access, using legitimate system utilities for data exfiltration, establishing reverse shells, or lateral movement.

Detection logic

FROM logs-aws.cloudtrail*, logs-endpoint.events.process-* METADATA _id, _version, _index
| WHERE
  // CloudTrail SSM SendCommand with AWS-RunShellScript
  (
    event.dataset == "aws.cloudtrail"
    AND event.action == "SendCommand"
    AND aws.cloudtrail.request_parameters LIKE "*documentName=AWS-RunShellScript*"
  )
  // Linux endpoint process events, prefiltered to SSM shell runner OR LOLBins/GTFOBins
  OR
  (
    event.dataset == "endpoint.events.process"
    AND host.os.type == "linux"
    AND (
      // SSM shell (_script.sh) runner
      process.command_line LIKE "%/document/orchestration/%/awsrunShellScript/%/_script.sh"
      // LOLBins / GTFOBins
      OR process.name IN (
        "base64",
        "curl",
        "wget",
        "openssl",
        "nc", "ncat", "netcat",
        "socat",
        "python", "python3",
        "perl",
        "php",
        "ruby",
        "ssh",
        "scp",
        "sftp",
        "rsync"
      )
    )
  )

// Endpoint leg: extract SSM command ID from parent command line
| DISSECT process.parent.command_line
    "%{}/document/orchestration/%{Esql.process_parent_command_line_ssm_command_id}/%{}"

// CloudTrail leg: extract SSM command ID from response_elements
| DISSECT aws.cloudtrail.response_elements
    "%{}commandId=%{Esql.aws_cloudtrail_response_elements_ssm_command_id},%{}"

// Coalesce SSM command ID from both data sources
| EVAL Esql.aws_ssm_command_id = COALESCE(
    Esql.aws_cloudtrail_response_elements_ssm_command_id,
    Esql.process_parent_command_line_ssm_command_id
)
| WHERE Esql.aws_ssm_command_id IS NOT NULL

// Role flags
| EVAL Esql.is_cloud_event    = event.dataset == "aws.cloudtrail"
| EVAL Esql.is_endpoint_event = event.dataset == "endpoint.events.process"

// Identify the SSM shell processes (the _script.sh runners)
| EVAL Esql.is_ssm_shell_process =
    Esql.is_endpoint_event
    AND process.command_line LIKE "%/document/orchestration/%/awsrunShellScript/%/_script.sh"

// LOLBins / GTFOBins on Linux
| EVAL Esql.is_lolbin_process =
    Esql.is_endpoint_event AND NOT Esql.is_ssm_shell_process

// Aggregate per SSM command ID
| STATS
    // Core correlation counts & timing
    Esql.aws_cloudtrail_event_count                 = SUM(CASE(Esql.is_cloud_event, 1, 0)),
    Esql.endpoint_events_process_lolbin_count       = SUM(CASE(Esql.is_lolbin_process, 1, 0)),
    Esql.endpoint_events_process_ssm_shell_count    = SUM(CASE(Esql.is_ssm_shell_process, 1, 0)),
    Esql.aws_cloudtrail_first_event_ts              = MIN(CASE(Esql.is_cloud_event, @timestamp, null)),
    Esql.endpoint_events_process_first_lolbin_ts    = MIN(CASE(Esql.is_lolbin_process, @timestamp, null)),

    // AWS / CloudTrail identity & request context
    Esql_priv.aws_cloudtrail_user_identity_arn_values          =
      VALUES(CASE(Esql.is_cloud_event, aws.cloudtrail.user_identity.arn, null)),
    Esql_priv.aws_cloudtrail_user_identity_access_key_id_values =
      VALUES(CASE(Esql.is_cloud_event, aws.cloudtrail.user_identity.access_key_id, null)),
    Esql_priv.user_name_values                                 =
      VALUES(CASE(Esql.is_cloud_event, user.name, null)),

    // AWS environment / request metadata
    Esql.cloud_region_values     = VALUES(CASE(Esql.is_cloud_event, cloud.region, null)),
    Esql.source_ip_values        = VALUES(CASE(Esql.is_cloud_event, source.ip, null)),
    Esql.user_agent_original_values =
      VALUES(CASE(Esql.is_cloud_event, user_agent.original, null)),

    // Endpoint host & user context
    Esql.host_name_values        = VALUES(CASE(Esql.is_endpoint_event, host.name, null)),
    Esql_priv.endpoint_user_name_values =
      VALUES(CASE(Esql.is_endpoint_event, user.name, null)),

    // SSM shell processes on endpoint
    Esql.process_command_line_ssm_shell_values =
      VALUES(CASE(Esql.is_ssm_shell_process, process.command_line, null)),
    Esql.process_pid_ssm_shell_values =
      VALUES(CASE(Esql.is_ssm_shell_process, process.pid, null)),

    // LOLBin processes on endpoint
    Esql.process_name_lolbin_values =
      VALUES(CASE(Esql.is_lolbin_process, process.name, null)),
    Esql.process_executable_lolbin_values =
      VALUES(CASE(Esql.is_lolbin_process, process.executable, null)),
    Esql.process_command_line_lolbin_values =
      VALUES(CASE(Esql.is_lolbin_process, process.command_line, null)),
    Esql.process_pid_lolbin_values =
      VALUES(CASE(Esql.is_lolbin_process, process.pid, null)),
    Esql.process_parent_command_line_lolbin_values =
      VALUES(CASE(Esql.is_lolbin_process, process.parent.command_line, null)),

    Esql.data_stream_namespace_values = VALUES(data_stream.namespace)
  BY Esql.aws_ssm_command_id

// Detection condition: SSM SendCommand + AWS-RunShellScript + LOLBin on endpoint
| WHERE Esql.aws_cloudtrail_event_count > 0
  AND Esql.endpoint_events_process_lolbin_count > 0
  AND DATE_DIFF(
        "minutes",
        Esql.endpoint_events_process_first_lolbin_ts,
        Esql.aws_cloudtrail_first_event_ts
      ) <= 5
| SORT Esql.aws_cloudtrail_first_event_ts ASC
| KEEP Esql.*, Esql_priv.*