Deprecated - Potential Password Spraying of Microsoft 365 User Accounts


Description

Identifies a high number (25) of failed Microsoft 365 user authentication attempts from a single IP address within 30 minutes, which could be indicative of a password spraying attack. An adversary may attempt a password spraying attack to obtain unauthorized access to user accounts.

Query · kuery

event.dataset:o365.audit and event.provider:(Exchange or AzureActiveDirectory) and event.category:authentication and
event.action:("UserLoginFailed" or "PasswordLogonInitialAuthUsingPassword")

Known false positives

  • Automated processes that attempt to authenticate using expired credentials and unbounded retries may lead to false positives.

Analyst notes

This rule has been deprecated in favor of Attempts to Brute Force a Microsoft 365 User Account (26f68dba-ce29-497b-8e13-b4fde1db5a2d).

Raw source Deprecated - Potential Password Spraying of Microsoft 365 User Accounts · Elastic TOML
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Published by elastic/detection-rules ↗, licensed under Elastic License 2.0 ↗. Reproduced here unmodified.
[metadata]
creation_date = "2020/12/01"
integration = ["o365"]
maturity = "deprecated"
deprecation_date = "2025/01/17"
updated_date = "2025/01/17"

[rule]
author = ["Elastic"]
description = """
Identifies a high number (25) of failed Microsoft 365 user authentication attempts from a single IP address within 30
minutes, which could be indicative of a password spraying attack. An adversary may attempt a password spraying attack to
obtain unauthorized access to user accounts.
"""
false_positives = [
    """
    Automated processes that attempt to authenticate using expired credentials and unbounded retries may lead to false
    positives.
    """,
]
from = "now-30m"
index = ["filebeat-*", "logs-o365*"]
language = "kuery"
license = "Elastic License v2"
name = "Deprecated - Potential Password Spraying of Microsoft 365 User Accounts"
note = """This rule has been deprecated in favor of `Attempts to Brute Force a Microsoft 365 User Account` (26f68dba-ce29-497b-8e13-b4fde1db5a2d)."""
risk_score = 73
rule_id = "3efee4f0-182a-40a8-a835-102c68a4175d"
severity = "high"
tags = [
    "Domain: Cloud",
    "Data Source: Microsoft 365",
    "Use Case: Identity and Access Audit",
    "Tactic: Credential Access",
]
timestamp_override = "event.ingested"
type = "threshold"

query = '''
event.dataset:o365.audit and event.provider:(Exchange or AzureActiveDirectory) and event.category:authentication and
event.action:("UserLoginFailed" or "PasswordLogonInitialAuthUsingPassword")
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1110"
name = "Brute Force"
reference = "https://attack.mitre.org/techniques/T1110/"


[rule.threat.tactic]
id = "TA0006"
name = "Credential Access"
reference = "https://attack.mitre.org/tactics/TA0006/"

[rule.threshold]
field = ["source.ip"]
value = 25

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