Detections

Explore public detection logic contributed by the community across SIEM and rule languages.

132 detections

'Identifies instances where Wazuh logged over 400 '403' Web Errors from one IP Address. To onboard Wazuh data into Sentinel please view: https://github.com/wazuh/wazuh-documentation/blob/master/source/azure/monitoring%20activity.rst'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0025
'Query over SigninLogs summarizes login attempts per hour on weekdays. Kusto anomaly detection finds login spikes. Calculates percentage change between anomalous period and average logins. Determines success and failure rate for logins for 1 hour period.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1024
'Identifies when 20 or more failed attempts from a given client IP in 1 minute occur on the IIS server.
This could be indicative of an attempted brute force. This could also simply indicate a misconfigured service or device.
Recommendations: Validate that these are expected connections from the given Client IP. If the client IP is not recognized, potentially block these connections at the edge device.
If these are expected connections, verify the credentials are properly configured on the system, service, application or device that is associated with the client IP.
References:
IIS status code mapping: https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0
Win32 Status code mapping: https://msdn.microsoft.com/library/cc231199.aspx'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2020
'Identifies IPs with failed attempts to sign in to one or more disabled accounts signed in successfully to another account.
To use this analytics rule, make sure you have deployed the [ASIM normalization parsers](https://aka.ms/ASimAuthentication)'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0019
'Identifies when 100 or more failed attempts by a given user in 10 minutes occur on the IIS Server.
This could be indicative of attempted brute force based on known account information.
This could also simply indicate a misconfigured service or device.
References:
IIS status code mapping - https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0
Win32 Status code mapping - https://msdn.microsoft.com/library/cc231199.aspx'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0017
'Identifies when failed logon attempts are 20 or higher during a 10 minute period (2 failed logons per minute minimum) from valid account.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0016
Detects failed logon attempts to MSSQL server instances, which can indicate brute-force attacks, password guessing, or credential stuffing attempts against database accounts. This rule specifically looks for Event ID 18456 from MSSQL providers in the Windows Application event log.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0026
The analytic identifies a single source IP failing to authenticate into Google Workspace with multiple valid users, potentially indicating a Password Spraying attack. It uses Google Workspace login failure events and calculates the standard deviation for source IPs, applying the 3-sigma rule to detect unusual failed authentication attempts. This activity is significant as it may signal an adversary attempting to gain initial access or elevate privileges. If confirmed malicious, this could lead to unauthorized access, data breaches, or further exploitation within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1071
The analytic detects attempts to authenticate using the built-in local Administrator account across more than 30 endpoints within a 5-minute window. It leverages Windows Event Logs, specifically events 4625 (failed logon) and 4624 (successful logon), to identify this behavior. This activity is significant as it may indicate an adversary attempting to validate stolen local credentials across multiple hosts, potentially leading to privilege escalation. If confirmed malicious, this could allow the attacker to gain widespread access and control over numerous systems within the network, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3066
The analytic detects a single source IP address failing to authenticate into more than 20 unique Google Workspace user accounts within a 5-minute window. It leverages Google Workspace login failure events to identify potential password spraying attacks. This activity is significant as it may indicate an adversary attempting to gain unauthorized access or elevate privileges within the Google Cloud Platform. If confirmed malicious, this behavior could lead to unauthorized access to sensitive resources, data breaches, or further exploitation within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1048
This analytic identifies an unusual number of failed authentication attempts to the AWS Console originating from a single source IP address, targeting multiple valid user accounts. It leverages AWS CloudTrail logs and statistical analysis (3-sigma rule) to detect anomalies in failed login attempts. This behavior is indicative of a password spraying attack, where an adversary attempts to gain initial access or elevate privileges by trying a single password against many accounts. Successful exploitation could lead to unauthorized access, data breaches, or further compromise of the AWS environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The following analytic identifies a spike in failed authentication attempts within an Office 365 environment, indicative of a potential distributed password spraying attack. It leverages UserLoginFailed events from O365 Management Activity logs, focusing on ErrorNumber 50126. This detection is significant as it highlights attempts to bypass security controls using multiple IP addresses and user agents. If confirmed malicious, this activity could lead to unauthorized access, data breaches, privilege escalation, and lateral movement within the organization. Early detection is crucial to prevent account takeovers and mitigate subsequent threats.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
The following analytic identifies instances where more than 10 unique user accounts fail to authenticate from a single IP address within a 5-minute window. This detection leverages O365 audit logs, specifically Azure Active Directory login failures (AzureActiveDirectoryStsLogon). Such activity is significant as it may indicate brute-force attacks or password spraying attempts. If confirmed malicious, this behavior suggests an external entity is attempting to breach security by targeting multiple accounts, potentially leading to unauthorized access. Immediate action is required to block or monitor the suspicious IP and notify affected users to enhance their security measures.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The analytic detects accounts experiencing a high number of Single Sign-On (SSO) logon errors within Office 365. It specifically looks for `UserLoginFailed` operations with `LogonError` containing "Sso" in the `o365_management_activity` data. A count of 5 or more such errors from the same source, vendor account, vendor product, destination, signature, and user agent within a given timeframe is considered anomalous. This activity can indicate brute-force attempts against SSO, credential stuffing, or attempts to reuse hijacked SSO tokens, potentially leading to unauthorized account access, data breaches, or further compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
The analytic detects an IP address with 20 or more failed authentication attempts to the AWS Web Console within a 5-minute window. This detection leverages CloudTrail logs, aggregating failed login events by IP address and time span. This activity is significant as it may indicate a brute force attack aimed at gaining unauthorized access or escalating privileges within an AWS environment. If confirmed malicious, this could lead to unauthorized access, data breaches, or further exploitation of AWS resources.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0035
The following analytic identifies an excessive number of authentication failures, including failed attempts against MFA prompt codes. It uses data from the `o365_management_activity` dataset, focusing on events where the authentication status is marked as failure. This behavior is significant as it may indicate a brute force attack or an attempt to compromise user accounts. If confirmed malicious, this activity could lead to unauthorized access, data breaches, or further exploitation within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0034
The analytic identifies instances where CrushFTP has blocked access due to exceeding the maximum number of simultaneous connections from a single IP address. This activity may indicate brute force attempts, credential stuffing, or automated attacks against the CrushFTP server. This detection is particularly relevant following the discovery of CVE-2025-31161, an authentication bypass vulnerability in CrushFTP versions 10.0.0 through 10.8.3 and 11.0.0 through 11.3.0.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
Detects instances where a MySQL service on an OpenCanary honeypot has had a login attempt. This indicates an adversary is attempting to gain unauthorized access to the honeypot's emulated MySQL service, which can be a sign of reconnaissance or credential stuffing activities.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1026
Detects when a high number of failed authentication attempts occur for unknown users on AWS, indicating a potential brute-force or credential stuffing attack against the AWS console.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
3069
This rule detects an unusual number of failed authentication attempts from the same IP address targeting valid users within an AWS environment. It specifically looks for 'ConsoleLogin' events from AWS CloudTrail where the security result indicates a 'BLOCK' action due to 'Failed authentication'. The rule triggers if there are more than 5 distinct target users experiencing failed logins from the same IP within a 5-minute window. Additionally, it calculates a risk score based on whether the source IP's country of origin is associated with known high-risk geographies (Cuba, Iran, North Korea, Russia, Syria).
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0060
This rule detects when an AWS user successfully authenticates to the AWS console from more than one unique IP address within a 5-minute window. This behavior can indicate a compromised account being accessed from multiple locations, potentially by different attackers, or by an attacker using a VPN/proxy service that rapidly changes IP addresses. The rule also includes an outcome that calculates a risk score based on successful logins originating from specific high-risk countries (Cuba, Iran, North Korea, Russia, Syria).
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0042
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