Detections

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

5,155 detections

This analytic detects executables running from public or temporary locations that are communicating over Windows domain authentication ports/protocols such as LDAP (389), LDAPS (636), and Kerberos (88). It leverages network traffic data to identify processes originating from user-controlled directories. This activity is significant because legitimate applications rarely run from these locations and attempt domain authentication, making it a potential indicator of compromise. If confirmed malicious, attackers could leverage this to access domain resources, potentially leading to further exploitation and lateral movement within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
This analytic detects suspicious `rundll32.exe` processes making DNS queries. This behavior is often associated with malware like IcedID, which uses `rundll32.exe` to check internet connectivity and communicate with command and control (C2) servers for configuration and payload downloads. Successful exploitation could lead to persistence, additional payload delivery, and data exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
The analytic identifies instances where CrushFTP has blocked access due to exceeding the maximum number of simultaneous connections from a single IP address. This activity may indicate brute force attempts, credential stuffing, or automated attacks against the CrushFTP server. This detection is particularly relevant following the discovery of CVE-2025-31161, an authentication bypass vulnerability in CrushFTP versions 10.0.0 through 10.8.3 and 11.0.0 through 11.3.0.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
The following analytic detects potential unauthorized access attempts exploiting CVE-2023-35082 within Ivanti's software products. It identifies access to the specific URI path /mifs/asfV3/api/v2/ with an HTTP 200 response code in web access logs, indicating successful unauthorized access. This activity is significant for a SOC as it highlights potential security breaches that could lead to unauthorized data access or system modifications. If confirmed malicious, an attacker could gain unbridled access to sensitive organizational data or modify systems maliciously, posing severe security risks.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
The analytic detects the initiation of traffic mirroring sessions on Cisco network devices. It leverages logs with specific mnemonics and facilities related to traffic mirroring, such as "ETH_SPAN_SESSION_UP" and "PKTCAP_START." This activity is significant because adversaries may use traffic mirroring to exfiltrate data by duplicating and forwarding network traffic to an external destination. If confirmed malicious, this could allow attackers to capture sensitive information, monitor network communications, and potentially compromise the integrity and confidentiality of the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0030
The analytic identifies an unusual number of Kerberos service ticket requests (Event ID 4769) originating from a single client address and account. It uses statistical analysis, specifically standard deviation and the 3-sigma rule, to detect anomalies. This activity is significant as it may indicate malicious behavior such as lateral movement, malware staging, or reconnaissance, potentially leading to unauthorized access to multiple endpoints and further compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0029
Detects an RDP connection originating from a domain controller. This activity is highly suspicious as domain controllers should not typically initiate RDP connections to other machines. Such an event could indicate lateral movement by an attacker who has compromised the domain controller. The rule specifically filters out connections made by "Microsoft.Tri.Sensor.exe", which is associated with Microsoft Defender for Identity, to avoid false positives from legitimate security operations.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0023
Detects network communication initiated to the 'portmap.io' domain. This domain is often associated with port forwarding services that can be abused by malicious actors for command and control (C2) communication or data exfiltration, potentially masking the true destination of the traffic.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0022
This rule detects when a Python process initiates an outbound network connection. While this activity can be legitimate for tasks like package installation or updates, it can also be indicative of malicious behavior, such as a Python-based script establishing communication with a command and control (C2) server or performing network reconnaissance. The rule includes filters to reduce false positives from common activities like Anaconda updates, Jupyter Notebook local communication, and 'pip install' commands.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0018
Detects programs that connect to known malware callback ports based on threat intelligence reports.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
001
Detects an executable accessing the portmap.io domain, which could be a sign of forbidden C2 traffic or data exfiltration by malicious actors
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
001
This YARA rule detects the Sshdinjector backdoor on Linux systems. It identifies specific byte patterns associated with the backdoor's functionalities, including killing and restarting daemons, network communication, reading the /etc/shadow file (for credential dumping), and listing running services.
ReversingLabs Yara@ReversingLabsYara
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ReversingLabs Yara
2 years ago
0057
Detects a Python process initiating a network connection. While this often relates to package installation, it can also indicate a potential malicious script communicating with a C&C server.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects the 'RegAsm.exe' utility initiating an outbound network connection to a public IP address. RegAsm.exe is a legitimate Microsoft utility used to register .NET assemblies, but it can be abused by adversaries for defense evasion and proxy execution, especially when making unexpected network connections.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
0016
This rule identifies enumeration of user inboxes within an Entra ID tenant via the Microsoft Graph API. It specifically looks for multiple GET requests to the `/v1.0/users/*/mailFolders/Inbox/messages` endpoint from a single IP address and session within a 5-minute window. The detection is based on the behavior of tools like Invoke-GraphOpenInboxFinder in GraphRunner, but is applicable to any tool performing similar inbox scanning. The rule provides outcomes detailing the number of scanned users, successful accesses (HTTP 200), forbidden accesses (HTTP 403), and not found inboxes (HTTP 404).
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
0052
Detects HTTP requests to low reputation TLDs (e.g. .xyz, .top, .ru) or ending in suspicious file extensions (.exe, .dll, .hta), which may indicate malicious activity.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Identify the use GraphRunner's Invoke-DumpApps function to collect applications and external apps as well as users that consented to permissions in their apps.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
001
Detects and alerts on users bypassing Chrome Safe Browsing warnings and accessing potentially dangerous content or downloads
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
000
Identify a 400 bad request to the groups endpoint in the MS Graph API. GraphRunner's Invoke-SecurityGroupCloner function will trigger this if it fails to duplicate a group.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
2 years ago
000
Detects a non-browser process interacting with the Google API which could indicate the use of a covert C2 such as Google Sheet C2 (GC2-sheet)
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
000
Detects network connections made by non-browser processes to public IP lookup services. This activity can indicate an adversary performing discovery to understand the external IP address of a compromised system, often as a post-compromise internet connectivity test or for reconnaissance purposes.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
2 years ago
1035
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