Detection rules › Panther

Teleport SSH Auth Errors

Severity
medium
Log types
Gravitational.TeleportAudit
Tags
SSH, Credential Access:Brute Force
Reference
https://goteleport.com/docs/management/admin/
Source
github.com/panther-labs/panther-analysis

A high volume of SSH errors could indicate a brute-force attack

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1110 Brute Force

Rule body yaml

AnalysisType: rule
Filename: teleport_auth_errors.py
RuleID: "Teleport.AuthErrors"
DisplayName: "Teleport SSH Auth Errors"
Enabled: true
LogTypes:
  - Gravitational.TeleportAudit
Tags:
  - SSH
  - Credential Access:Brute Force
Severity: Medium
Reports:
  MITRE ATT&CK:
    - TA0006:T1110
Description: A high volume of SSH errors could indicate a brute-force attack
Threshold: 10
DedupPeriodMinutes: 15
Reference: https://goteleport.com/docs/management/admin/
Runbook: >
  Check that the user making the failed requests legitimately tried logging in that many times.
SummaryAttributes:
  - event
  - code
  - user
  - program
  - path
  - return_code
  - login
  - server_id
  - sid
Tests:
  - Name: SSH Errors
    ExpectedResult: true
    Log:
      {
        "code": "T3007W",
        "error": 'ssh: principal "jack" not in the set of valid principals for given certificate: ["ec2-user"]',
        "event": "auth",
        "success": false,
        "time": "2020-08-13T18:39:42Z",
        "uid": "53e474cc-db1c-45f1-a60d-b31239e20098",
        "user": "panther",
      }
  - Name: Echo command
    ExpectedResult: false
    Log:
      {
        "argv": [],
        "cgroup_id": 4294967537,
        "code": "T4000I",
        "ei": 15,
        "event": "session.command",
        "login": "root",
        "namespace": "default",
        "path": "/bin/echo",
        "pid": 7143,
        "ppid": 7115,
        "program": "echo",
        "return_code": 0,
        "server_id": "e75992b4-9e27-456f-b1c9-7a32da83c661",
        "sid": "8a3fc038-785b-43f3-8737-827b3e25fe5b",
        "time": "2020-08-17T17:40:37.491Z",
        "uid": "8eaf8f39-09d4-4a42-a22a-65163d2af702",
        "user": "panther",
      }

Detection logic

Condition

error is_not_null
event eq "auth"

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
erroris_not_null
  • (no value, null check)
eventeq
  • auth

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field
user
cluster_name