FROM logs-azure.signinlogs*
| EVAL
time_window = DATE_TRUNC(15 minutes, @timestamp),
user_id = TO_LOWER(azure.signinlogs.properties.user_principal_name),
ip = source.ip,
login_error = azure.signinlogs.result_description,
error_code = azure.signinlogs.properties.status.error_code,
request_type = TO_LOWER(azure.signinlogs.properties.incoming_token_type),
app_name = TO_LOWER(azure.signinlogs.properties.app_display_name),
asn_org = source.`as`.organization.name,
country = source.geo.country_name,
user_agent = user_agent.original,
event_time = @timestamp
| WHERE event.dataset == "azure.signinlogs"
AND event.category == "authentication"
AND azure.signinlogs.category IN ("NonInteractiveUserSignInLogs", "SignInLogs")
AND azure.signinlogs.properties.resource_display_name RLIKE "(.*)365|SharePoint|Exchange|Teams|Office(.*)"
AND event.outcome == "failure"
AND error_code != 50053
AND azure.signinlogs.properties.status.error_code IN (
50034, // UserAccountNotFound
50126, // InvalidUsernameOrPassword
50055, // PasswordExpired
50056, // InvalidPassword
50057, // UserDisabled
50064, // CredentialValidationFailure
50076, // MFARequiredButNotPassed
50079, // MFARegistrationRequired
50105, // EntitlementGrantsNotFound
70000, // InvalidGrant
70008, // ExpiredOrRevokedRefreshToken
70043, // BadTokenDueToSignInFrequency
80002, // OnPremisePasswordValidatorRequestTimedOut
80005, // OnPremisePasswordValidatorUnpredictableWebException
50144, // InvalidPasswordExpiredOnPremPassword
50135, // PasswordChangeCompromisedPassword
50142, // PasswordChangeRequiredConditionalAccess
120000, // PasswordChangeIncorrectCurrentPassword
120002, // PasswordChangeInvalidNewPasswordWeak
120020 // PasswordChangeFailure
)
AND user_id IS NOT NULL AND user_id != ""
AND user_agent != "Mozilla/5.0 (compatible; MSAL 1.0) PKeyAuth/1.0"
| STATS
authentication_requirement = VALUES(azure.signinlogs.properties.authentication_requirement),
client_app_id = VALUES(azure.signinlogs.properties.app_id),
client_app_display_name = VALUES(azure.signinlogs.properties.app_display_name),
target_resource_id = VALUES(azure.signinlogs.properties.resource_id),
target_resource_display_name = VALUES(azure.signinlogs.properties.resource_display_name),
conditional_access_status = VALUES(azure.signinlogs.properties.conditional_access_status),
device_detail_browser = VALUES(azure.signinlogs.properties.device_detail.browser),
device_detail_device_id = VALUES(azure.signinlogs.properties.device_detail.device_id),
device_detail_operating_system = VALUES(azure.signinlogs.properties.device_detail.operating_system),
incoming_token_type = VALUES(azure.signinlogs.properties.incoming_token_type),
risk_state = VALUES(azure.signinlogs.properties.risk_state),
session_id = VALUES(azure.signinlogs.properties.session_id),
user_id = VALUES(azure.signinlogs.properties.user_id),
user_principal_name = VALUES(azure.signinlogs.properties.user_principal_name),
result_description = VALUES(azure.signinlogs.result_description),
result_signature = VALUES(azure.signinlogs.result_signature),
result_type = VALUES(azure.signinlogs.result_type),
unique_users = COUNT_DISTINCT(user_id),
user_id_list = VALUES(user_id),
login_errors = VALUES(login_error),
unique_login_errors = COUNT_DISTINCT(login_error),
error_codes = VALUES(error_code),
unique_error_codes = COUNT_DISTINCT(error_code),
request_types = VALUES(request_type),
app_names = VALUES(app_name),
ip_list = VALUES(ip),
unique_ips = COUNT_DISTINCT(ip),
source_orgs = VALUES(asn_org),
countries = VALUES(country),
unique_country_count = COUNT_DISTINCT(country),
unique_asn_orgs = COUNT_DISTINCT(asn_org),
first_seen = MIN(event_time),
last_seen = MAX(event_time),
total_attempts = COUNT()
BY time_window
| EVAL
duration_seconds = DATE_DIFF("seconds", first_seen, last_seen),
bf_type = CASE(
// Many users, relatively few distinct login errors, distributed over multiple IPs (but not too many),
// and happens quickly. Often bots using leaked credentials.
unique_users >= 10 AND total_attempts >= 30 AND unique_login_errors <= 3
AND unique_ips >= 5
AND duration_seconds <= 600
AND unique_users > unique_ips,
"credential_stuffing",
// One password against many users. Single error (e.g., "InvalidPassword"), not necessarily fast.
unique_users >= 15 AND unique_login_errors == 1 AND total_attempts >= 15 AND duration_seconds <= 1800,
"password_spraying",
// One user targeted repeatedly (same error), OR extremely noisy pattern from many IPs.
(unique_users == 1 AND unique_login_errors == 1 AND total_attempts >= 30 AND duration_seconds <= 300)
OR (unique_users <= 3 AND unique_ips > 30 AND total_attempts >= 100),
"password_guessing",
// everything else
"other"
)
| KEEP
time_window, bf_type, duration_seconds, total_attempts, first_seen, last_seen,
unique_users, user_id_list, login_errors, unique_login_errors,
unique_error_codes, error_codes, request_types, app_names,
ip_list, unique_ips, source_orgs, countries,
unique_country_count, unique_asn_orgs,
authentication_requirement, client_app_id, client_app_display_name,
target_resource_id, target_resource_display_name, conditional_access_status,
device_detail_browser, device_detail_device_id, device_detail_operating_system,
incoming_token_type, risk_state, session_id, user_id,
user_principal_name, result_description, result_signature, result_type
| WHERE bf_type != "other"
Install detection rules in Elastic Security
Detect Microsoft 365 Brute Force via Entra ID Sign-Ins in the Elastic Security detection engine by installing this rule into your Elastic Stack.
To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).