Detections

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

1,666 detections

This rule detects potential session token replay attacks in Azure Active Directory by correlating interactive or single-factor sign-in events using 'python-requests' user agents (common in automated tooling) with subsequent 'Register device' and 'Register security info' (Windows Hello for Business) activity within a 48-hour window. This behavior often indicates an adversary attempting to register a device to a compromised account to maintain persistence or bypass MFA requirements.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
2 months ago
408
Detects anomalous authentication patterns indicative of session token replay attacks. The rule identifies instances where a user successfully performs an MFA-authenticated, interactive sign-in, followed shortly (within 5-60 minutes) by a single-factor sign-in for the same user. The suspicious activity is characterized by a shift to a different IP/ASN, an unmanaged device (non-trusted), and a change in browser or OS identifiers, all while the user's geolocation (city/country) remains consistent. This behavioral pattern is highly consistent with the use of residential proxy infrastructure to replay stolen session tokens, effectively bypassing MFA.
avatar
Arnold Chan@slaz
avatar
Detection & Hunting Community
2 months ago
002
Detects anomalous authentication patterns indicative of session token replay attacks. The rule identifies instances where a user successfully performs an MFA-authenticated, interactive sign-in, followed shortly (within 5-60 minutes) by a single-factor sign-in for the same user. The suspicious activity is characterized by a shift to a different IP/ASN, an unmanaged device (non-trusted), and a change in browser or OS identifiers, all while the user's geolocation (city/country) remains consistent. This behavioral pattern is highly consistent with the use of residential proxy infrastructure to replay stolen session tokens, effectively bypassing MFA.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
002
Detects anomalous authentication patterns indicative of session token replay attacks. The rule identifies instances where a user successfully performs an MFA-authenticated, interactive sign-in, followed shortly (within 5-60 minutes) by a single-factor sign-in for the same user. The suspicious activity is characterized by a shift to a different IP/ASN, an unmanaged device (non-trusted), and a change in browser or OS identifiers, all while the user's geolocation (city/country) remains consistent. This behavioral pattern is highly consistent with the use of residential proxy infrastructure to replay stolen session tokens, effectively bypassing MFA.
avatar
Arnold Chan@slaz
avatar
Detections.ai Community
2 months ago
102
Detects anomalous sign-in behavior where a device code authentication flow is initiated from one location, but the resulting session is replayed from a different IP address in a different country within a one-hour window. This behavior is indicative of an adversary capturing an authentication token via a device code phishing or relay attack and attempting to use it from their own infrastructure to bypass conditional access policies and MFA.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
001
Detects a suspicious sequence of interactive sign-ins to Microsoft management and profile-related applications from unmanaged devices occurring within a tight 15-minute window. This behavior is indicative of post-compromise activity, potentially associated with activity clusters such as UNC6671, where an attacker interacts with account settings shortly after compromising a session.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
102
Detects a suspicious sequence of interactive sign-ins to Microsoft management and profile-related applications from unmanaged devices occurring within a tight 15-minute window. This behavior is indicative of post-compromise activity, potentially associated with activity clusters such as UNC6671, where an attacker interacts with account settings shortly after compromising a session.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
2 months ago
002
Detects a suspicious sequence of interactive sign-ins to Microsoft management and profile-related applications from unmanaged devices occurring within a tight 15-minute window. This behavior is indicative of post-compromise activity, potentially associated with activity clusters such as UNC6671, where an attacker interacts with account settings shortly after compromising a session.
avatar
Arnold Chan@slaz
avatar
Detection & Hunting Community
2 months ago
002
This rule detects user authentication events that deviate significantly from a 14-day historical baseline of known devices, operating systems, browsers, and network locations (ASN). It flags logins where at least two out of four key metadata signals (DeviceId, OS, Browser, ASN) have changed compared to the user's historical pattern, specifically targeting successful authentications that did not trigger a fresh multi-factor authentication (MFA) challenge, potentially indicating token theft or unauthorized session reuse.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
2 months ago
002
Detects successful Azure AD sign-ins where the user agent identifies as a Python requests library version (2.33.1 or 2.34.2) that has not been observed for that specific user account in the preceding 14 days. This behavior is indicative of anomalous automated or scripted access.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
002
Detects Microsoft 365 sign-in events where a session token is reused without a fresh MFA challenge, originating from known residential proxy service providers. This behavior is indicative of threat actors using stolen session tokens (Session Replay) to bypass MFA protections.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
002
This rule monitors Azure AD Sign-in logs to identify 'impossible travel' scenarios, where a user authenticates successfully from two geographically distant locations within a time window (1 hour) that would require travel speeds exceeding a plausible threshold. This behavior is a common indicator of credential compromise or session token replay attacks.
avatar
Ankit Mehta@Secvyn
avatar
SlimKQL
2 months ago
101
Detects non-interactive sign-in events involving OIDC or external authentication tokens shortly after a known Coder registry compromise. The rule flags high-risk or at-risk single-factor authentication sessions, which may indicate the replay of stolen tokens harvested during the compromise window.
avatar
Arnold Chan@slaz
avatar
Hunters
2 months ago
000
Detects anomalous authentication patterns indicative of session token replay attacks. The rule identifies instances where a user successfully performs an MFA-authenticated, interactive sign-in, followed shortly (within 5-60 minutes) by a single-factor sign-in for the same user. The suspicious activity is characterized by a shift to a different IP/ASN, an unmanaged device (non-trusted), and a change in browser or OS identifiers, all while the user's geolocation (city/country) remains consistent. This behavioral pattern is highly consistent with the use of residential proxy infrastructure to replay stolen session tokens, effectively bypassing MFA.
avatar
Arnold Chan@slaz
avatar
Hunters
2 months ago
000
Detects a suspicious sequence of interactive sign-ins to Microsoft management and profile-related applications from unmanaged devices occurring within a tight 15-minute window. This behavior is indicative of post-compromise activity, potentially associated with activity clusters such as UNC6671, where an attacker interacts with account settings shortly after compromising a session.
avatar
Arnold Chan@slaz
avatar
Hunters
2 months ago
000
Detects successful Azure AD sign-ins where the user agent identifies as a Python requests library version (2.33.1 or 2.34.2) that has not been observed for that specific user account in the preceding 14 days. This behavior is indicative of anomalous automated or scripted access.
avatar
Arnold Chan@slaz
avatar
Hunters
2 months ago
000
Detects a privilege escalation technique where an attacker with application management permissions adds a credential to the 'Office 365 Exchange Online' service principal (SP). The attacker then leverages the SP's 'Domain.ReadWrite.All' permission to add or modify a federated domain, allowing them to forge tokens for any hybrid user.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
003
Detects successful authentication attempts to a LiteLLM proxy instance using the hardcoded default master key 'sk-1234'. This activity indicates potential exploitation of misconfigured instances where default credentials remain unchanged.
avatar
Arnold Chan@slaz
avatar
Midnight Slayer
2 months ago
000
Detects successful authentication attempts to a LiteLLM proxy instance using the hardcoded default master key 'sk-1234'. This activity indicates potential exploitation of misconfigured instances where default credentials remain unchanged.
avatar
Arnold Chan@slaz
avatar
Detection & Hunting Community
2 months ago
000
Detects successful authentication attempts to a LiteLLM proxy instance using the hardcoded default master key 'sk-1234'. This activity indicates potential exploitation of misconfigured instances where default credentials remain unchanged.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
000
Detects successful VPN logins following a burst of failed attempts from multiple IP addresses, where the successful login originates from a known malicious IP or an IP associated with the preceding failed attempts. This rule specifically identifies potential credential stuffing or password spraying activity targeting VPN services, often associated with the BlackSuit ransomware group.
avatar
Arnold Chan@slaz
Defender - KQL
2 months ago
001
Page 44 of 80