Teleport: Update Rules (#966)

* Teleport: Update Rules * Update global_helpers/panther_default.py * Update global_helpers/panther_default.py * Update rules/gravitational_teleport_rules/teleport_long_lived_certs.py Co-authored-by: Ariel Ropek <[email protected]> * Update rules/gravitational_teleport_rules/teleport_long_lived_certs.py Co-authored-by: Ariel Ropek <[email protected]> * Update rules/gravitational_teleport_rules/teleport_long_lived_certs.py Co-authored-by: Ariel Ropek <[email protected]> * Update rules/gravitational_teleport_rules/teleport_long_lived_certs.py * Update rules/gravitational_teleport_rules/teleport_long_lived_certs.py * Update rules/gravitational_teleport_rules/teleport_long_lived_certs.py * Update rules/gravitational_teleport_rules/teleport_long_lived_certs.py appease fmt * Update rules/gravitational_teleport_rules/teleport_long_lived_certs.py --------- Co-authored-by: Ariel Ropek <[email protected]>
panther-labs · Nov 27, 2023 · 1f8841b · 1f8841b
1 parent 6252b95
commit 1f8841b
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diff --git a/global_helpers/panther_base_helpers.py b/global_helpers/panther_base_helpers.py
@@ -2,6 +2,7 @@
 import re
 from collections import OrderedDict
 from collections.abc import Mapping
+from datetime import datetime
 from fnmatch import fnmatch
 from functools import reduce
 from ipaddress import ip_address, ip_network
@@ -494,3 +495,22 @@ def m365_alert_context(event):
 def defang_ioc(ioc):
     """return defanged IOC from 1.1.1.1 to 1[.]1[.]1[.]1"""
     return ioc.replace(".", "[.]")
+
+
+def panther_nanotime_to_python_datetime(panther_time: str) -> datetime:
+    panther_time_micros = re.search(r"\.(\d+)", panther_time).group(1)
+    panther_time_micros_rounded = panther_time_micros[0:6]
+    panther_time_rounded = re.sub(r"\.\d+", f".{panther_time_micros_rounded}", panther_time)
+    panther_time_format = r"%Y-%m-%d %H:%M:%S.%f"
+    return datetime.strptime(panther_time_rounded, panther_time_format)
+
+
+def golang_nanotime_to_python_datetime(golang_time: str) -> datetime:
+    golang_time_format = r"%Y-%m-%dT%H:%M:%S.%fZ"
+    # Golang fractional seconds include a mix of microseconds and
+    # nanoseconds, which doesn't play well with Python's microseconds datetimes.
+    # This rounds the fractional seconds to a microsecond-size.
+    golang_time_micros = re.search(r"\.(\d+)Z", golang_time).group(1)
+    golang_time_micros_rounded = golang_time_micros[0:6]
+    golang_time_rounded = re.sub(r"\.\d+Z", f".{golang_time_micros_rounded}Z", golang_time)
+    return datetime.strptime(golang_time_rounded, golang_time_format)
diff --git a/rules/gravitational_teleport_rules/teleport_auth_errors.py b/rules/gravitational_teleport_rules/teleport_auth_errors.py
@@ -5,5 +5,6 @@ def rule(event):
 def title(event):
     return (
         f"A high volume of SSH errors was detected from user "
-        f"[{event.get('user', '<UNKNOWN_USER>')}]"
+        f"[{event.get('user', '<UNKNOWN_USER>')}] "
+        f"on [{event.get('cluster_name', '<UNKNOWN_CLUSTER>')}]"
     )
diff --git a/rules/gravitational_teleport_rules/teleport_auth_errors.yml b/rules/gravitational_teleport_rules/teleport_auth_errors.yml
@@ -15,7 +15,7 @@ Reports:
 Description: A high volume of SSH errors could indicate a brute-force attack
 Threshold: 10
 DedupPeriodMinutes: 15
-Reference: https://gravitational.com/teleport/docs/admin-guide/
+Reference: https://goteleport.com/docs/management/admin/
 Runbook: >
   Check that the user making the failed requests legitimately tried logging in that many times.
 SummaryAttributes:

diff --git a/rules/gravitational_teleport_rules/teleport_create_user_accounts.py b/rules/gravitational_teleport_rules/teleport_create_user_accounts.py
@@ -16,4 +16,7 @@ def rule(event):
 
 
 def title(event):
-    return f"User [{event.get('user', '<UNKNOWN_USER>')}] has manually modified system users"
+    return (
+        f"User [{event.get('user', '<UNKNOWN_USER>')}] has manually modified system users "
+        f"on [{event.get('cluster_name', '<UNKNOWN_CLUSTER>')}]"
+    )
diff --git a/rules/gravitational_teleport_rules/teleport_create_user_accounts.yml b/rules/gravitational_teleport_rules/teleport_create_user_accounts.yml
@@ -14,7 +14,7 @@ Reports:
 Severity: High
 Description: A user has been manually created, modified, or deleted
 DedupPeriodMinutes: 15
-Reference: https://gravitational.com/teleport/docs/admin-guide/
+Reference: https://goteleport.com/docs/management/admin/
 Runbook: Analyze why it was manually created and delete it if necessary.
 SummaryAttributes:
   - event

diff --git a/rules/gravitational_teleport_rules/teleport_local_user_login_without_mfa.py b/rules/gravitational_teleport_rules/teleport_local_user_login_without_mfa.py
@@ -0,0 +1,24 @@
+SENSITIVE_LOCAL_USERS = ["breakglass"]
+
+
+def rule(event):
+    return (
+        event.get("event") == "user.login"
+        and event.get("success") == "true"
+        and event.get("method") == "local"
+        and not event.get("mfa_device")
+    )
+
+
+def severity(event):
+    if event.get("user") in SENSITIVE_LOCAL_USERS:
+        return "HIGH"
+    return "MEDIUM"
+
+
+def title(event):
+    return (
+        f"User [{event.get('user', '<UNKNOWN_USER>')}] logged into "
+        f"[{event.get('cluster_name', '<UNNAMED_CLUSTER>')}] locally "
+        f"without using MFA"
+    )
diff --git a/rules/gravitational_teleport_rules/teleport_local_user_login_without_mfa.yml b/rules/gravitational_teleport_rules/teleport_local_user_login_without_mfa.yml
@@ -0,0 +1,64 @@
+AnalysisType: rule
+Filename: teleport_local_user_login_without_mfa.py
+RuleID: Teleport.LocalUserLoginWithoutMFA
+DisplayName: User Logged in wihout MFA
+Enabled: true
+LogTypes:
+  - Gravitational.TeleportAudit
+Tags:
+  - Teleport
+Severity: High
+Description: A local User logged in without MFA
+DedupPeriodMinutes: 60
+Reports:
+  MITRE ATT&CK:
+    - TA0001:T1078
+Reference: https://goteleport.com/docs/management/admin/
+Runbook: >
+  A local user logged in without Multi-Factor Authentication
+SummaryAttributes:
+  - event
+  - code
+  - user
+  - success
+  - mfa_device
+Tests:
+  -
+    Name: User logged in with MFA
+    ExpectedResult: false
+    Log:
+      {
+        "addr.remote": "[2001:db8:feed:face:c0ff:eeb0:baf00:00d]:65123",
+        "cluster_name": "teleport.example.com",
+        "code": "T1000I",
+        "ei": 0,
+        "event": "user.login",
+        "method": "local",
+        "mfa_device": {
+          "mfa_device_name": "1Password",
+          "mfa_device_type": "WebAuthn",
+          "mfa_device_uuid": "88888888-4444-4444-4444-222222222222"
+        },
+        "success": true,
+        "time": "2023-09-20T19:00:00.123456Z",
+        "uid": "88888888-4444-4444-4444-222222222222",
+        "user": "max.mustermann",
+        "user_agent": "Examplecorp Spacedeck-web/99.9 (Hackintosh; ARM Cortex A1000)"
+      }
+  -
+    Name: User logged in without MFA
+    ExpectedResult: false
+    Log:
+      {
+        "addr.remote": "[2001:db8:face:face:face:face:face:face]:65123",
+        "cluster_name": "teleport.example.com",
+        "code": "T1000I",
+        "ei": 0,
+        "event": "user.login",
+        "method": "local",
+        "success": true,
+        "time": "2023-09-20T19:00:00.123456Z",
+        "uid": "88888888-4444-4444-4444-222222222222",
+        "user": "max.mustermann",
+        "user_agent": "Examplecorp Spacedeck-web/99.9 (Hackintosh; ARM Cortex A1000)"
+      }
diff --git a/rules/gravitational_teleport_rules/teleport_lock_created.py b/rules/gravitational_teleport_rules/teleport_lock_created.py
@@ -0,0 +1,10 @@
+def rule(event):
+    return event.get("event") == "lock.created"
+
+
+def title(event):
+    return (
+        f"A Teleport Lock was created by {event.get('updated_by', '<UNKNOWN_UPDATED_BY>')} "
+        f"to Lock out user {event.get('target', {}).get('user', '<UNKNOWN_USER>')} "
+        f"on [{event.get('cluster_name', '<UNKNOWN_CLUSTER>')}]"
+    )
diff --git a/rules/gravitational_teleport_rules/teleport_lock_created.yml b/rules/gravitational_teleport_rules/teleport_lock_created.yml
@@ -0,0 +1,40 @@
+AnalysisType: rule
+Filename: teleport_lock_created.py
+RuleID: Teleport.LockCreated
+DisplayName: A Teleport Lock was created
+Enabled: true
+LogTypes:
+  - Gravitational.TeleportAudit
+Tags:
+  - Teleport
+Severity: Info
+Description: A Teleport Lock was created
+DedupPeriodMinutes: 60
+Reference: https://goteleport.com/docs/management/admin/
+Runbook: >
+  A Teleport Lock was created; this is an unusual administrative action. Investigate to understand why a Lock was created.
+SummaryAttributes:
+  - event
+  - code
+  - time
+  - identity
+Tests:
+  -
+    Name: A Lock was created
+    ExpectedResult: true
+    Log:
+      {
+        "cluster_name": "teleport.example.com",
+        "code": "TLK00I",
+        "ei": 0,
+        "event": "lock.created",
+        "expires": "0001-01-01T00:00:00Z",
+        "name": "88888888-4444-4444-4444-222222222222",
+        "target": {
+          "user": "user-to-disable"
+        },
+        "time": "2023-09-21T00:00:00.000000Z",
+        "uid": "88888888-4444-4444-4444-222222222222",
+        "updated_by": "[email protected]",
+        "user": "[email protected]"
+      }
diff --git a/rules/gravitational_teleport_rules/teleport_long_lived_certs.py b/rules/gravitational_teleport_rules/teleport_long_lived_certs.py
@@ -0,0 +1,79 @@
+from datetime import timedelta, datetime
+from typing import Dict, Tuple
+
+from panther_base_helpers import (
+    golang_nanotime_to_python_datetime,
+    panther_nanotime_to_python_datetime,
+)
+
+PANTHER_TIME_FORMAT = r"%Y-%m-%d %H:%M:%S.%f"
+# Tune this to be some Greatest Common Denominator of session TTLs for your
+# environment
+MAXIMUM_NORMAL_VALIDITY_INTERVAL = timedelta(hours=12)
+# To allow some time in between when a request is submitted and authorized
+# vs when the certificate actually gets generated. In practice, this is much
+# less than 5 seconds.
+ISSUANCE_GRACE_PERIOD = timedelta(seconds=5)
+
+# You can audit your logs in Panther to try and understand your role/validity
+# patterns from a known-good period of access.
+# A query example:
+# ```sql
+#  SELECT
+#     cluster_name,
+#     identity:roles,
+#     DATEDIFF('HOUR', time, identity:expires) AS validity
+#  FROM
+#     panther_logs.public.gravitational_teleportaudit
+#  WHERE
+#     p_occurs_between('2023-09-01 00:00:00','2023-10-06 21:00:00Z')
+#     AND event = 'cert.create'
+#  GROUP BY cluster_name, identity:roles, validity
+#  ORDER BY validity DESC
+# ```
+
+# A dictionary of:
+#  cluster names: to a dictionary of:
+#     role names: mapping to a tuple of:
+#        ( maximum usual validity, expiration datetime for this rule )
+CLUSTER_ROLE_MAX_VALIDITIES: Dict[str, Dict[str, Tuple[timedelta, datetime]]] = {
+    # "teleport.example.com": {
+    #     "example_role": (timedelta(hours=720), datetime(2023, 12, 01, 01, 02, 03)),
+    #     "other_example_role": (timedelta(hours=720), datetime.max),
+    # },
+}
+
+
+def rule(event):
+    if not event.get("event") == "cert.create":
+        return False
+    max_validity = MAXIMUM_NORMAL_VALIDITY_INTERVAL + ISSUANCE_GRACE_PERIOD
+    for role in event.deep_get("identity", "roles", default=[]):
+        validity, expiration = CLUSTER_ROLE_MAX_VALIDITIES.get(event.get("cluster_name"), {}).get(
+            role, (None, None)
+        )
+        if validity and expiration:
+            # Ignore exceptions that have passed their expiry date
+            if datetime.utcnow() < expiration:
+                max_validity = max(max_validity, validity)
+    return validity_interval(event) > max_validity
+
+
+def validity_interval(event):
+    event_time = panther_nanotime_to_python_datetime(event.get("time"))
+    expires = golang_nanotime_to_python_datetime(
+        event.deep_get("identity", "expires", default=None)
+    )
+    if not event_time and expires:
+        return False
+    interval = expires - event_time
+    return interval
+
+
+def title(event):
+    identity = event.deep_get("identity", "user", default="<Cert with no User!?>")
+    return (
+        f"A Certificate for [{identity}] "
+        f"on [{event.get('cluster_name', '<UNKNOWN_CLUSTER>')}] "
+        f"has been issued for an unusually long time: {validity_interval(event)!r} "
+    )
diff --git a/rules/gravitational_teleport_rules/teleport_long_lived_certs.yml b/rules/gravitational_teleport_rules/teleport_long_lived_certs.yml
@@ -0,0 +1,92 @@
+AnalysisType: rule
+Filename: teleport_long_lived_certs.py
+RuleID: Teleport.LongLivedCerts
+DisplayName: A long-lived cert was created
+Enabled: true
+LogTypes:
+  - Gravitational.TeleportAudit
+Tags:
+  - Teleport
+Severity: Medium
+Description: An unusually long-lived Teleport certificate was created
+DedupPeriodMinutes: 60
+Reports:
+  MITRE ATT&CK:
+    - TA0003:T1098
+Reference: https://goteleport.com/docs/management/admin/
+Runbook: >
+  Teleport certificates are usually issued for a short period of time. Alert if long-lived certificates were created.
+SummaryAttributes:
+  - event
+  - code
+  - time
+  - identity
+Tests:
+  -
+    Name: A certificate was created for the default period of 1 hour
+    ExpectedResult: false
+    Log:
+      {
+        "cert_type": "user",
+        "cluster_name": "teleport.example.com",
+        "code": "TC000I",
+        "ei": 0,
+        "event": "cert.create",
+        "time": "2023-09-17 21:00:00.000000",
+        "identity": {
+          "disallow_reissue": true,
+          "expires": "2023-09-17T22:00:00.444444428Z",
+          "impersonator": "bot-application",
+          "kubernetes_cluster": "staging",
+          "kubernetes_groups": [
+            "application"
+          ],
+          "logins": [
+            "-teleport-nologin-88888888-4444-4444-4444-222222222222",
+            "-teleport-internal-join"
+          ],
+          "prev_identity_expires": "0001-01-01T00:00:00Z",
+          "roles": [
+            "application"
+          ],
+          "route_to_cluster": "teleport.example.com",
+          "teleport_cluster": "teleport.example.com",
+          "traits": {},
+          "user": "bot-application"
+        },
+        "uid": "88888888-4444-4444-4444-222222222222"
+      }
+  -
+    Name: A certificate was created for longer than the default period of 1 hour
+    ExpectedResult: true
+    Log:
+      {
+        "cert_type": "user",
+        "cluster_name": "teleport.example.com",
+        "code": "TC000I",
+        "ei": 0,
+        "event": "cert.create",
+        "time": "2023-09-17 21:00:00.000000",
+        "identity": {
+          "disallow_reissue": true,
+          "expires": "2043-09-17T22:00:00.444444428Z",
+          "impersonator": "bot-application",
+          "kubernetes_cluster": "staging",
+          "kubernetes_groups": [
+            "application"
+          ],
+          "logins": [
+            "-teleport-nologin-88888888-4444-4444-4444-222222222222",
+            "-teleport-internal-join"
+          ],
+          "prev_identity_expires": "0001-01-01T00:00:00Z",
+          "roles": [
+            "application"
+          ],
+          "route_to_cluster": "teleport.example.com",
+          "teleport_cluster": "teleport.example.com",
+          "traits": {},
+          "user": "bot-application"
+        },
+        "uid": "88888888-4444-4444-4444-222222222222"
+      }
diff --git a/rules/gravitational_teleport_rules/teleport_network_scanning.py b/rules/gravitational_teleport_rules/teleport_network_scanning.py
@@ -12,5 +12,6 @@ def rule(event):
 def title(event):
     return (
         f"User [{event.get('user', '<UNKNOWN_USER>')}] has issued a network scan with "
-        f"[{event.get('program', '<UNKNOWN_PROGRAM>')}]"
+        f"[{event.get('program', '<UNKNOWN_PROGRAM>')}] "
+        f"on [{event.get('cluster_name', '<UNKNOWN_CLUSTER>')}]"
     )
diff --git a/rules/gravitational_teleport_rules/teleport_network_scanning.yml b/rules/gravitational_teleport_rules/teleport_network_scanning.yml
@@ -14,7 +14,7 @@ DedupPeriodMinutes: 60
 Reports:
   MITRE ATT&CK:
     - TA0007:T1046
-Reference: https://gravitational.com/teleport/docs/admin-guide/
+Reference: https://goteleport.com/docs/management/admin/
 Runbook: >
   Find related commands within the time window and determine if the command was invoked legitimately. Examine the arguments to determine how the command was used.
 SummaryAttributes: