Detections

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

309 detections

This rule detects successful SSH authentication attempts originating from IP addresses that are not classified as private (non-RFC1918). It specifically looks for log entries indicating 'Accepted password' or 'Accepted publickey' and then filters out source IP addresses that fall within common private IPv4 ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 127.0.0.0/8, 169.254.0.0/16). The rule is designed to identify SSH access from external networks, which might be unusual in environments where SSH is expected to be primarily internal. It does not account for IPv6 private addresses.
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Jorden Smith@Jorden
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SimSpace Public
9 months ago
2079
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
The following analytic identifies the execution of RAR utilities to archive files on a system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, GUIDs, and command-line arguments. This activity is significant as threat actors, including red-teamers and malware like DarkGate, use RAR archiving to compress and exfiltrate collected data from compromised hosts. If confirmed malicious, this behavior could lead to the unauthorized transfer of sensitive information to command and control servers, posing a severe risk to data confidentiality and integrity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1042
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 scenarios where an attacker enables the OpenSSH server and server starts to listening on SSH socket.
SIGMA Detection Rules@SIGMADetectionRules
SIGMA Detection Rules
1 year ago
006
The analytic detects when a Windows RDP client attempts to execute an RDP file from a temporary directory, downloads directory, or Outlook directories. This detection is significant as it can indicate an attempt for an adversary to deliver a .rdp file, which may be leveraged by attackers to control or exfiltrate data. If confirmed malicious, this activity could lead to unauthorized access, data theft, or further lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0059
The analytic identifies the execution of the native mimikatz.exe binary on Windows systems, including instances where the binary is renamed. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and original file names. This activity is significant because Mimikatz is a widely used tool for extracting authentication credentials, posing a severe security risk. If confirmed malicious, this activity could allow attackers to obtain sensitive credentials, escalate privileges, and move laterally within the network, leading to potential data breaches and system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0055
KQL Query
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
6076
KQL Query
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
6061
KQL Query from file: DefenderXDR Exposure Management for CVE-2024-3094
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
2055
KQL Query
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
2054
KQL Query
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
5051
KQL Query
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Steven Lim@KQLWizard
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SlimKQL
1 year ago
4038
'Azure AD Connect (AAD Connect) is a critical service that handles connections between on-premise Active Directory and Azure AD.
Due to the critical nature of AAD Connect threat actors may attempt to compromise the service in order to access credentials.
This query looks for SSH connections to host that appear to run AAD Connect. The results should be reviewed to determine if the
SSH connection is legitimate.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0037
Intent:
- Use MTP capability to look for insider threat potential risk indicators
- Indicators would then serve as the building block for insider threat risk modeling in subsequent tools
Definition of Insider Threat:
"The potential for an individual who has or had authorized access to an organization's assets to use their access, either maliciously or unintentionally, to act in a way that could negatively affect the organization."
This collection of queries describes the different indicators that could be used to model and look for patterns suggesting an increased risk of an individual becoming a potential insider threat.
Note: no single indicator should be used as a lone determinant of insider threat activity, but should be part of an overall program to understand the increased risk to your organization's critical assets. This in turn is used to feed an investigation by a formal insider threat program to look at the context associated with the whole person to understand the implication of a set of indicators.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1030
Detects scenarios where an attacker enables the OpenSSH server and server starts to listening on SSH socket.
Yamato Security Hayabusa@YamatoSecurityHayabusa
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Yamato Security Hayabusa Rules
1 year ago
005
This analytic detects suspicious modifications to Unix shell configuration files, such as `.bashrc` or `.profile`, which may indicate an attempt to alter system behavior or gain unauthorized access. Unauthorized changes to these files can be used to execute malicious commands, escalate privileges, or hide malicious activities. By monitoring for unusual or unauthorized modifications to shell configuration files, this analytic helps identify potential security threats, allowing security teams to respond quickly and mitigate risks.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
4088
The following analytic detects attempts to stop a service on Linux systems. It leverages data from Linux Auditd. This activity is significant as adversaries often stop or terminate security or critical services to disable defenses or disrupt operations, as seen in malware like Industroyer2. If confirmed malicious, this could lead to the disabling of security mechanisms, allowing attackers to persist, escalate privileges, or deploy destructive payloads, severely impacting system integrity and availability.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0054
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