Detections

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

67 detections

Detects when a successful MFA authentication occurs due to the use of a bypass code.
A bypass code is a temporary passcode created by an administrator for a specific user to access a Duo-protected application. These are generally used as "backup codes," so that enrolled users who are having problems with their mobile devices (e.g., mobile service is disrupted, the device is lost or stolen, etc.) or who temporarily can't use their enrolled devices (on a plane without mobile data services) can still access their Duo-protected systems.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
6 months ago
000
This rule detects when a user marks an authentication request as fraudulent within Duo Security. This indicates a potential attempt to gain unauthorized access to a user's account, possibly through MFA fatigue or other social engineering tactics. The rule specifically looks for 'user_marked_fraud' in the security result summary of Duo authentication events.
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The Bishop@bishop
Google SecOps
7 months ago
40102
Detects when a successful multi-factor authentication (MFA) occurs due to the use of a bypass code in Cisco Duo. Bypass codes are temporary passcodes created by administrators for specific users to access Duo-protected applications, typically used as backup codes when users cannot use their enrolled devices. This rule identifies instances where such a bypass code facilitates a successful authentication.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
2154
The following analytic detects the use of default or publicly known named pipes associated with Cobalt Strike. It leverages Sysmon EventID 17 and 18 to identify specific named pipes commonly used by Cobalt Strike's Artifact Kit and Malleable C2 Profiles. This activity is significant because Cobalt Strike is a popular tool for adversaries to conduct post-exploitation tasks, and identifying its named pipes can reveal potential malicious activity. If confirmed malicious, this could indicate an active Cobalt Strike beacon, leading to unauthorized access, data exfiltration, or further lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
100247
This analytic detects suspicious data transfer activities involving the use of the `split` syscall with the `-b` option, which specifies the size of each output file. This technique can be used by attackers to evade detection by breaking large files into smaller parts, bypassing size-based security controls, and facilitating covert exfiltration of sensitive data. By monitoring for unusual or unauthorized use of the `split` syscall with a specified block size, this analytic helps identify potential data exfiltration attempts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0087
This analytic identifies the bulk creation of ransomware notes (e.g., .txt, .html, .hta files) on an infected machine. It leverages Sysmon EventCode 11 to detect multiple instances of these file types being created within a short time frame (10 seconds). A detection is triggered if 15 or more unique readme paths are observed. This activity is a strong indicator of an active ransomware attack, where the attacker is notifying the victim of the encryption. If confirmed malicious, this behavior could lead to widespread data encryption, rendering critical files inaccessible and potentially causing significant operational disruption.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1160
The following analytic detects suspicious attempts to find credentials stored in password stores, indicating a potential attacker's effort to access sensitive login information. Password stores are critical repositories that contain valuable credentials, and unauthorized access to them can lead to significant security breaches. By monitoring for unusual or unauthorized activities related to password store access, this analytic helps identify potential credential theft attempts, allowing security teams to respond promptly and prevent unauthorized access to critical systems and data.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0056
Detects potential Adversary-in-the-Middle (AiTM) phishing activity, commonly associated with frameworks like Evilginx. The rule identifies suspicious domain patterns where legitimate identity provider (IdP) domains are used as subdomains of another domain, or where IdP-related keywords are used in hyphenated subdomains.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
50184
This analytic detects the configuration of TFTP services on Cisco IOS devices that could be used to exfiltrate sensitive configuration files. Threat actors like Static Tundra have been observed configuring TFTP servers to make device configuration files accessible for exfiltration after gaining initial access. The detection specifically looks for commands that expose critical configuration files such as startup-config, running-config, and other sensitive system information through TFTP. This activity is particularly concerning as it may represent an attempt to steal credentials, network topology information, and other sensitive data stored in device configurations.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1059
Detects multiple failed Multi-Factor Authentication (MFA) push attempts for a user from a single IP address, followed by a successful attempt within a short time window. This pattern can indicate an MFA push bombing or fatigue attack where an adversary spams a user with MFA requests until they approve one.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
100136
Detects a high number of failed or denied Multi-Factor Authentication (MFA) attempts followed by a success for the same user account within a short time frame. This pattern, known as MFA fatigue or push bombing, is a technique actively used by threat actors like Scattered Spider to overwhelm a user with push notifications until they approve one, granting the attacker access.
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Aaron Mog@amog
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Detections.ai Community
1 year ago
100179
The following analytic detects instances where a Duo admin login originates from a country outside of the United States, which may indicate suspicious or unauthorized access attempts. It works by analyzing Duo activity logs for admin login actions and filtering out events where the access device's country is not within the expected region. By correlating user, device, browser, and location details, the analytic highlights anomalies in geographic login patterns. This behavior is critical for a SOC to identify because admin accounts have elevated privileges, and access from unusual countries can be a strong indicator of credential compromise, account takeover, or targeted attacks. Early detection of such activity enables rapid investigation and response, reducing the risk of unauthorized changes, data breaches, or further lateral movement within the environment. The impact of this attack can be severe, potentially allowing attackers to bypass security controls, alter configurations, or exfiltrate sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
100111
The analytic detects when a Duo policy is created or updated to allow network-based bypass of two-factor authentication (2FA). It identifies this behavior by searching Duo administrator logs for policy creation or update actions where the networks_allow field is present, indicating that specific networks have been permitted to bypass 2FA requirements. This is achieved by parsing the event description and filtering for relevant policy changes, then aggregating the results by user and administrator details. Detecting this behavior is critical for a Security Operations Center (SOC) because allowing network-based 2FA bypass can significantly weaken authentication controls, potentially enabling unauthorized access if a trusted network is compromised or misconfigured. Attackers or malicious insiders may exploit this policy change to circumvent 2FA protections, increasing the risk of account takeover and lateral movement within the environment. Prompt detection enables SOC analysts to investigate and respond to potentially risky policy modifications before they can be leveraged for malicious purposes.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2090
The analytic identifies Cisco Duo admin login attempts originating from operating systems that are unusual for the environment, specifically excluding commonly used OS like Mac OS X. It analyzes Duo activity logs for 'admin_login' actions and filters out expected operating systems. The rule then aggregates events by browser, version, source IP, location, and OS details to highlight anomalies. Detecting admin logins from unexpected operating systems is crucial for a Security Operations Center (SOC) as it may indicate credential compromise, unauthorized access, or attacker activity using unfamiliar devices. Such behavior can precede privilege escalation, policy changes, or other malicious actions within the Duo environment. Early detection enables rapid investigation and response, reducing the risk of account takeover and minimizing potential damage to organizational security controls.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
5068
The following analytic detects instances where a Duo administrator performs a bulk deletion of more than three policies in a single action. It identifies this behavior by searching Duo activity logs for the policy_bulk_delete action, extracting the names of deleted policies, and counting them. If the count exceeds three, the event is flagged. This behavior is significant for a Security Operations Center (SOC) because mass deletion of security policies can indicate malicious activity, such as an attacker or rogue administrator attempting to weaken or disable security controls, potentially paving the way for further compromise. Detecting and investigating such actions promptly is critical, as the impact of this attack could include reduced security posture, increased risk of unauthorized access, and potential data breaches. Monitoring for bulk policy deletions helps ensure that any suspicious or unauthorized changes to security configurations are quickly identified and addressed to protect organizational assets and maintain compliance.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2068
The analytic detects instances where a Duo user's status is changed to "Bypass" for 2FA, specifically when the previous status was "Active." This behavior is identified by analyzing Duo activity logs for user update actions, extracting the status transitions, and filtering for cases where a user is set to bypass multi-factor authentication. This is a critical event for a Security Operations Center (SOC) to monitor, as bypassing 2FA significantly weakens account security and may indicate malicious insider activity or account compromise. Attackers or unauthorized administrators may exploit this change to disable strong authentication controls, increasing the risk of unauthorized access to sensitive systems and data. Early detection of such changes enables rapid investigation and response, helping to prevent potential breaches and limit the impact of credential-based attacks.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0064
The following analytic detects when a Duo user generates a bypass code, which allows them to circumvent multi-factor authentication (2FA) protections. It works by monitoring Duo activity logs for the 'bypass_create' action, renaming the affected object as the user, and aggregating events to identify instances where a bypass code is issued. This behavior is significant for a Security Operations Center (SOC) because generating a bypass code can enable attackers, malicious insiders, or unauthorized administrators to gain access to sensitive systems without the required second authentication factor. Such activity may indicate account compromise, privilege abuse, or attempts to weaken security controls. Early detection of bypass code generation is critical, as it allows the SOC to investigate and respond before an attacker can exploit the reduced authentication requirements, helping to prevent unauthorized access, data breaches, or further lateral movement within the environment. Monitoring for this action helps maintain strong authentication standards and reduces the risk of credential-based attacks.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1055
The analytic identifies instances where a Duo administrator creates or updates a policy to allow the use of outdated Flash components, specifically by detecting policy changes with the `flash_remediation=no remediation` attribute. This behavior is significant because permitting old Flash increases the attack surface due to known vulnerabilities. Attackers may exploit such policy changes to bypass security controls, introduce malware, or escalate privileges. Detecting these modifications helps prevent potential exploitation and reduces organizational risk. Immediate investigation is recommended to determine if the change was authorized or indicative of malicious activity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1049
The analytic identifies instances where a Duo admin logs in using a browser other than Chrome, which is considered unusual based on typical access patterns. This behavior is significant for a SOC because the use of an unexpected browser may indicate credential compromise, session hijacking, or the use of unauthorized devices by attackers attempting to evade detection. Detecting such anomalies enables early investigation and response, helping to prevent privilege escalation, policy manipulation, or further compromise of sensitive administrative accounts. The impact of this attack could include unauthorized changes to security policies, user access, or the disabling of critical security controls, posing a substantial risk to the organizations security posture.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3053
The analytic detects instances where a Duo policy is created or updated to allow access without two-factor authentication (2FA). It identifies this behavior by searching Duo administrator activity logs for policy changes that set the authentication status to "Allow access without 2FA." By monitoring for these specific actions, the analytic highlights potential attempts to weaken authentication controls, which could be indicative of malicious activity or insider threats. This behavior is critical for a SOC to identify, as bypassing 2FA significantly reduces the security posture of an organization, making it easier for attackers to gain unauthorized access to sensitive systems and data. Detecting and responding to such policy changes promptly helps prevent potential account compromise and mitigates the risk of broader security breaches.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic detects when a Duo policy is created or updated to allow access without two-factor authentication (2FA) for users in countries other than the default. It identifies this behavior by searching Duo administrator activity logs for policy creation or update actions where the policy description indicates that access is permitted without 2FA for certain user locations. This is achieved by parsing the relevant fields in the logs and filtering for the specific condition of 'Allow access without 2FA.' This behavior is significant for a Security Operations Center (SOC) because bypassing 2FA for any user group or location weakens the organization's security posture and increases the risk of unauthorized access. Attackers or malicious insiders may exploit such policy changes to circumvent strong authentication controls, potentially leading to account compromise, data breaches, or lateral movement within the environment. Early detection of these policy modifications enables the SOC to investigate and respond before attackers can leverage the weakened controls, thereby reducing the risk and impact of a successful attack.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
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