Detections

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

455 detections

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
Detects successful Okta authentication using the FIDO/WebAuthn cross-device (hybrid) sign-in feature. This technique is abused by attackers in Adversary-in-the-Middle (AiTM) phishing campaigns, like those conducted by PoisonSeed, to bypass FIDO MFA by tricking a user into scanning a malicious QR code.
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Jason Nelson@Jason
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Detections.ai Community
1 year ago
2297
Detects successful user authentication using the FIDO2/WebAuthn cross-device (hybrid) sign-in feature. This technique can be abused by attackers in Adversary-in-the-Middle (AiTM) phishing campaigns to bypass FIDO key protections, as seen in the PoisonSeed campaign.
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Jason Nelson@Jason
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Detections.ai Community
1 year ago
1238
KQL Query from file: Detecting FIDO2 Passkey Abuse
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
50114
KQL Query from file: Hunting Rockstar 2FA
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
8097
KQL Query
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
7075
Detects suspicious AWS API calls to DeactivateMFADevice and DeleteVirtualMFADevice, which may indicate attempts to disable MFA and evade detection.
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Lingesh R@bakerexpress
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Detections.ai Community
1 year ago
5363
Looks for a new MFA method added to an account that was preceded by medium or high risk sign-in session for the same user within maximum 6h timeframe
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
4071
'Detects successful signins using single factor authentication where the device, location, and ASN are abnormal.
Single factor authentications pose an opportunity to access compromised accounts, investigate these for anomalous occurrencess.
Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-devices#non-compliant-device-sign-in'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
3066
Detects changes to the "StrongAuthenticationRequirement" value, where the state is set to "0" or "Disabled".
Threat actors were seen disabling multi factor authentication for users in order to maintain or achieve access to the account. Also see in SIM Swap attacks.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
101
'Identifies an interrupted sign-in session from a country the user has not sign-in before in the last 7 days, where the password was correct. Although the session is interrupted by other controls such as multi factor authentication or conditional access policies, the user credentials should be reset due to logs indicating a correct password was observed during sign-in.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
6028
The following analytic identifies the registration of a new Multi-Factor Authentication (MFA) method for an AWS account, as logged through Amazon Security Lake (ASL). It detects this activity by monitoring the `CreateVirtualMFADevice` API operation within ASL logs. This behavior is significant because adversaries who gain unauthorized access to an AWS account may register a new MFA method to maintain persistence. If confirmed malicious, this activity could allow attackers to secure their access, making it harder to detect and remove their presence from the compromised environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The following analytic detects attempts to disable multi-factor authentication (MFA) for an Azure AD user. It leverages Azure Active Directory AuditLogs to identify the "Disable Strong Authentication" operation. This activity is significant because disabling MFA can allow adversaries to maintain persistence using compromised accounts without raising suspicion. If confirmed malicious, this action could enable attackers to bypass an essential security control, potentially leading to unauthorized access and prolonged undetected presence in the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3078
The following analytic identifies instances where new IP addresses are added to the trusted IPs list in Office 365, potentially allowing users from these IPs to bypass Multi-Factor Authentication (MFA) during login. It leverages O365 audit logs, specifically focusing on events related to the modification of trusted IP settings. This activity is significant because adding trusted IPs can weaken the security posture by bypassing MFA, which is a critical security control. If confirmed malicious, this could lead to unauthorized access, compromising sensitive information and systems. Immediate investigation is required to validate the legitimacy of the IP addition.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2152
The following analytic detects attempts to disable multi-factor authentication (MFA) for an AWS IAM user. It leverages AWS CloudTrail logs to identify events where MFA devices are deleted or deactivated. This activity is significant because disabling MFA can indicate an adversary attempting to weaken account security, potentially to maintain persistence using a compromised account. If confirmed malicious, this action could allow attackers to retain access to the AWS environment without detection, posing a significant risk to the security and integrity of the cloud infrastructure.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
The analytic detects unusual authentication activity in Azure AD, specifically when a single user account has over 8 authentication attempts using 3+ unique application IDs and 5+ unique user agents within a short period. This behavior is significant as it may indicate an adversary probing for MFA requirements or attempting to bypass MFA. If confirmed malicious, it suggests a compromised account, potentially leading to further exploitation, lateral movement, and data exfiltration. Early detection is crucial to prevent substantial harm.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
The following analytic identifies instances where Multi-Factor Authentication (MFA) is disabled for a user within the Office 365 environment. It leverages O365 audit logs, specifically focusing on events related to MFA settings. Disabling MFA removes a critical security layer, making accounts more vulnerable to unauthorized access. If confirmed malicious, this activity could indicate an attacker attempting to maintain persistence or an insider threat, significantly increasing the risk of unauthorized access. Immediate investigation is required to validate the reason for disabling MFA, potentially re-enable it, and assess any other suspicious activities related to the affected account.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0050
The following analytic detects attempts to disable multi-factor authentication (MFA) for an AWS IAM user. It leverages Amazon Security Lake logs, specifically monitoring for `DeleteVirtualMFADevice` or `DeactivateMFADevice` API operations. This activity is significant as disabling MFA can indicate an adversary attempting to weaken account security to maintain persistence using a compromised account. If confirmed malicious, this action could allow attackers to retain access to the AWS environment without detection, potentially leading to unauthorized access to sensitive resources and prolonged compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1049
This analytic identifies failed authentication attempts against an Azure AD tenant during the Multi-Factor Authentication (MFA) challenge, specifically flagged by error code 500121. It leverages Azure AD SignInLogs to detect these events. This activity is significant as it may indicate an adversary attempting to authenticate using compromised credentials on an account with MFA enabled. If confirmed malicious, this could suggest an ongoing effort to bypass MFA protections, potentially leading to unauthorized access and further compromise of the affected account.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0048
The following analytic identifies unusual authentication activity in an O365 environment, where a single user account experiences more than 8 authentication attempts using 3 or more unique application IDs and over 5 unique user agents within a short timeframe. It leverages O365 audit logs, focusing on authentication events and applying statistical thresholds. This behavior is significant as it may indicate an adversary probing for multi-factor authentication weaknesses. If confirmed malicious, it suggests a compromised account, potentially leading to unauthorized access, privilege escalation, and data exfiltration. Early detection is crucial to prevent further exploitation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
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