Detections

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

4,308 detections

The following analytic identifies unsuccessful login attempts to the AWS Management Console using a specific user identity. It leverages AWS CloudTrail logs to detect failed authentication events associated with the AWS ConsoleLogin action. This activity is significant for a SOC because repeated failed login attempts may indicate a brute force attack or unauthorized access attempts. If confirmed malicious, an attacker could potentially gain access to AWS account services and resources, leading to data breaches, resource manipulation, or further exploitation within the AWS environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2044
This analytic identifies an unusual number of Kerberos service ticket requests (Event 4769) from a single host, which can indicate a Kerberoasting attack. It calculates the standard deviation of unique service requests per user and source, using the 3-sigma rule to detect anomalies. Kerberoasting allows adversaries to obtain and crack service tickets offline, potentially leading to privileged access and escalation within an Active Directory environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1044
This analytic detects changes to the sIDHistory attribute of user or computer objects within the same domain. It leverages Windows Security Event Codes 4738 (User Account Changed) and 4742 (Computer Account Changed) to identify when the sIDHistory attribute is modified. This activity is significant because the sIDHistory attribute can be abused by adversaries to grant unauthorized access by inheriting permissions from another account. If confirmed malicious, this could allow attackers to maintain persistent access or escalate privileges within the domain, posing a severe security risk. The rule specifically looks for cases where the added SID History matches the target SID or target domain name, indicating an attempt to add a SID from the same domain.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1044
The analytic detects a single source process failing to authenticate with 30 or more unique users, indicating a potential Password Spraying attack. It leverages Windows Event 4625 with Logon Type 2, collected from domain controllers, member servers, and workstations. This activity is significant as it may represent an adversary attempting to gain initial access or elevate privileges within an Active Directory environment. If confirmed malicious, this could lead to unauthorized access, privilege escalation, or further compromise of the network, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The following analytic detects the execution of known MailSniper PowerShell functions on a machine. It leverages PowerShell logs (EventCode 4104) to identify specific script block text associated with MailSniper activities. This behavior is significant as MailSniper is often used by attackers to harvest sensitive emails from compromised Exchange servers. If confirmed malicious, this activity could lead to unauthorized access to sensitive email data, credential theft, and further compromise of the email infrastructure.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3043
The analytic detects a suspicious computer account name change in Active Directory. It leverages Event ID 4781, which logs account name changes, to identify instances where a computer account name is changed to one that does not end with a '$'. This behavior is significant as it may indicate an attempt to exploit CVE-2021-42278 and CVE-2021-42287, which can lead to domain controller impersonation and privilege escalation. If confirmed malicious, this activity could allow an attacker to gain elevated privileges and potentially control the domain.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
This analytic detects the execution of the `Get-DomainSPNTicket` commandlet, which is part of the PowerView tool, by monitoring PowerShell Script Block Logging (EventCode=4104). This commandlet is used to request Kerberos service tickets for specified Service Principal Names (SPNs). Detecting this activity is critical because it can indicate attempts to perform Kerberoasting, a technique where attackers extract SPN account passwords for offline cracking. If this activity is confirmed to be malicious, it could lead to unauthorized access to sensitive accounts, potentially resulting in privilege escalation and further compromise of the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0043
The analytic detects an Azure AD account successfully authenticating from multiple unique IP addresses within a 30-minute window. It leverages Azure AD SignInLogs to identify instances where the same user logs in from different IPs in a short time frame. This behavior is significant as it may indicate compromised credentials being used by an adversary, potentially following a phishing attack. If confirmed malicious, this activity could allow unauthorized access to corporate resources, leading to data breaches or further exploitation within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1042
The analytic identifies AWS console login events by users from a new city within the last hour. It leverages AWS CloudTrail events and compares them against a lookup file of previously seen user locations. This activity is significant for a SOC as it may indicate unauthorized access or credential compromise, especially if the login originates from an unusual location. If confirmed malicious, this could lead to unauthorized access to AWS resources, data exfiltration, or further exploitation within the cloud environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The following analytic detects suspicious attempts to find credentials stored in password managers, which may indicate an attacker's effort to retrieve sensitive login information. Password managers are often targeted by adversaries seeking to access stored passwords for further compromise or lateral movement within a network. By monitoring for unusual or unauthorized access to password manager files or processes, this analytic helps identify potential credential theft attempts, enabling security teams to respond quickly to protect critical accounts and prevent further unauthorized access.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
This detection identifies an Active Directory access-control list (ACL) modification event, which applies the minimum required extended rights to perform the DCShadow attack. Specifically, it looks for modifications to the domainDNS object where specific GUIDs related to 'Add/Remove Replica In Domain', 'Manage Replication Topology', and 'Replication Synchronization' are added to the ACL. These permissions are necessary for an attacker to register a rogue domain controller and perform a DCShadow attack.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1042
The analytic detects the creation of files containing passwords, cookies, and saved login account information by the Braodo stealer malware in temporary folders. Braodo often collects these credentials from browsers and applications, storing them in temp directories before exfiltration. This detection focuses on monitoring for the creation of files with patterns or formats commonly associated with stolen credentials. By identifying these activities, security teams can take needed action to prevent sensitive login data from being leaked, reducing the risk of unauthorized access to user accounts and systems.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1042
This analytic detects an unusual number of NTLM authentications targeting a single destination using a null domain. This activity is indicative of an attacker attempting to brute force or password spray a domain-joined Windows device from a non-domain device. Such activity may also generate a high volume of EventID 4776 events, though these events might not specify the attacker or target device.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The analytic detects a single source IP failing to authenticate with 30 unique valid users within 5 minutes in Azure Active Directory. It leverages Azure AD SignInLogs with error code 50126, indicating invalid passwords. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges by trying common passwords across many accounts. If confirmed malicious, this activity could lead to unauthorized access, data breaches, or privilege escalation within the Azure AD environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The following analytic detects a process accessing the winlogon.exe system process, indicative of the Rubeus tool attempting to export Kerberos tickets from memory. This detection leverages Sysmon EventCode 10 logs, focusing on processes obtaining a handle to winlogon.exe with specific access rights. This activity is significant as it often precedes pass-the-ticket attacks, where adversaries use stolen Kerberos tickets to move laterally within an environment. If confirmed malicious, this could allow attackers to bypass normal access controls, escalate privileges, and persist within the network, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The analytic detects the creation of files with extensions commonly associated with the Mimikatz Crypto module. It leverages the Endpoint.Filesystem data model to identify specific file names indicative of certificate export activities. This behavior is significant as it may indicate the use of Mimikatz to export cryptographic keys, which is a common tactic for credential theft. If confirmed malicious, this activity could allow an attacker to exfiltrate sensitive cryptographic material, potentially leading to unauthorized access and further compromise of the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The following analytic identifies a single source endpoint failing to authenticate with 30 unique users using the Kerberos protocol. It leverages EventCode 4771 with Status 0x18, indicating wrong password attempts, and aggregates these events over a 5-minute window. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges in an Active Directory environment. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, and potential compromise of sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
This analytic detects suspicious processes accessing registry entries related to default internet browsers. It specifically looks for Windows Security Event Code 4663, which indicates an attempt to access registry paths associated with browser configurations. Adversaries often target these registry keys to gather information about installed browsers and their settings, which can lead to the theft of sensitive data like login credentials and browsing history. The rule filters out common legitimate processes to reduce false positives. If confirmed malicious, this activity could enable attackers to exfiltrate sensitive information and compromise user accounts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
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 a Kerberos Ticket Granting Ticket (TGT) request using RC4-HMAC encryption (type 0x17) by leveraging Event 4768. This encryption type is outdated and its presence may indicate an OverPass The Hash attack. Monitoring this activity is crucial as it can signify credential theft, allowing adversaries to authenticate to the Kerberos Distribution Center (KDC) using a stolen NTLM hash. If confirmed malicious, this could enable unauthorized access to systems and resources, potentially leading to lateral movement and further compromise within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0040
The following analytic detects the use of Mimikatz command line parameters associated with pass-the-ticket attacks. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command-line patterns related to Kerberos ticket manipulation. This activity is significant because pass-the-ticket attacks allow adversaries to move laterally within an environment using stolen Kerberos tickets, bypassing normal access controls. If confirmed malicious, this could enable attackers to escalate privileges, access sensitive information, and maintain persistence within the network.
Splunk Security@SplunkSecurity
avatar
Splunk Security Content
1 year ago
0040
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