Detections

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

462 detections

This rule detects the creation or modification of files associated with the Shai-Hulud 2.0 worm. The detection is based on specific file hashes and a behavioral rule for an unusually large 'bun_environment.js' file, which is a key indicator of the malware's obfuscation techniques.
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Mehulkumar Savajani@Msavajani
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Detections.ai Community
11 months ago
1089
Detects the creation of a set of four named pipes with a specific naming convention (`[random]_stdin_read`, `[random]_stdin_write`, etc.), a behavior consistent with the EndClient RAT used by Kimsuky to establish a remote shell.
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Tim Peck@timpeck
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Detections.ai Community
1 year ago
1155
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
The following analytic detects PowerShell processes launched with command-line arguments indicative of obfuscation techniques. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, parent processes, and complete command-line executions. This activity is significant because obfuscated PowerShell commands are often used by attackers to evade detection and execute malicious scripts. If confirmed malicious, this activity could lead to unauthorized code execution, privilege escalation, or persistent access within the environment, posing a significant security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
10100
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
The following analytic detects the creation of screen capture files by the Braodo stealer malware. This stealer is known to capture screenshots of the victim's desktop as part of its data theft activities. The detection focuses on identifying unusual screen capture activity, especially when images are saved in directories often used by malware, such as temporary or hidden folders. Monitoring for these files helps to quickly identify malicious screen capture attempts, allowing security teams to respond and mitigate potential information exposure before sensitive data is compromised.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2053
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 analytic detects suspicious PowerShell execution indicative of PowerShell-Empire activity. It leverages PowerShell Script Block Logging (EventCode=4104) to capture and analyze commands sent to PowerShell, specifically looking for patterns involving `system.net.webclient` and base64 encoding. This behavior is significant as it often represents initial stagers used by PowerShell-Empire, a known post-exploitation framework. If confirmed malicious, this activity could allow attackers to download and execute additional payloads, leading to potential code execution, data exfiltration, or further compromise of the affected system.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
3058
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 detects suspicious usage of BitLockerToGo.exe, which has been observed being abused by Lumma stealer malware. The malware leverages this legitimate Windows utility to manipulate registry keys, search for cryptocurrency wallets and credentials, and exfiltrate sensitive data. This activity is significant because BitLockerToGo.exe provides functionality for viewing, copying, and writing files as well as modifying registry branches - capabilities that the Lumma stealer exploits for malicious purposes. If confirmed malicious, this could indicate an active data theft campaign targeting cryptocurrency wallets, browser credentials, and password manager archives. The detection focuses on identifying BitLockerToGo.exe execution patterns that deviate from normal system behavior.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1052
This analytic identifies suspicious PowerShell script execution via EventCode 4104 that contains multiple URLs within a function or array. This pattern is often indicative of obfuscated scripts or those attempting to download secondary payloads. Such activity may signal an attempt to execute malicious code, download additional malware, lead to further system compromise, or data exfiltration. Review parallel processes and the full script block for additional context and related artifacts.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0049
This analytic detects the presence of "api.telegram.org" in the command line of a process. This activity is significant because the Telegram API has been used as an exfiltration mechanism or as a Command and Control (C2) channel by adversaries. If confirmed malicious, this could indicate an attacker or malware is exfiltrating data or receiving additional C2 instructions, potentially leading to further compromise and persistence within the network. The rule leverages process execution logs from Endpoint Detection and Response (EDR) agents.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0048
The analytic detects FTP connections initiated by processes located in non-standard installation paths on Windows systems. It leverages Sysmon EventCode 3 to identify network connections where the process image path does not match common directories like "Program Files" or "Windows\System32". This activity is significant as FTP is often used by adversaries and malware, such as AgentTesla, for Command and Control (C2) communications to exfiltrate stolen data. If confirmed malicious, this could lead to unauthorized data transfer, exposing sensitive information and compromising the integrity of the affected host.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0042
The following analytic detects the modification of SSH Authorized Keys on Linux systems. It leverages process execution data from Endpoint Detection and Response (EDR) agents, specifically monitoring commands like "bash" and "cat" interacting with "authorized_keys" files. This activity is significant as adversaries often modify SSH Authorized Keys to establish persistent access to compromised endpoints. If confirmed malicious, this behavior could allow attackers to maintain unauthorized access, bypassing traditional authentication mechanisms and potentially leading to further exploitation or data exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1039
The analytic detects file writes with extensions indicative of a SamSam ransomware attack. It leverages file-system activity data to identify file names ending in .stubbin, .berkshire, .satoshi, .sophos, or .keyxml. This activity is significant because SamSam ransomware is highly destructive, leading to file encryption and ransom demands. If confirmed malicious, the impact includes significant financial losses, operational disruptions, and reputational damage. Immediate actions should include isolating affected systems, restoring files from backups, and investigating the attack source to prevent further incidents.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The analytic detects the execution of `gpupdate.exe` without command line arguments and with an active network connection. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process execution and network traffic data. It is significant because `gpupdate.exe` typically runs with specific arguments, and its execution without them, especially with network activity, is often associated with malicious software like Cobalt Strike. If confirmed malicious, this activity could indicate an attacker leveraging `gpupdate.exe` for lateral movement, command and control, or other nefarious purposes, potentially leading to system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0033
The following analytic detects process injection into Notepad.exe using Sysmon EventCode 10. It identifies suspicious GrantedAccess requests (0x40 and 0x1fffff) to Notepad.exe, excluding common system paths like System32, Syswow64, and Program Files. This behavior is often associated with the SliverC2 framework by BishopFox. Monitoring this activity is crucial as it may indicate an initial payload attempting to execute malicious code within Notepad.exe. If confirmed malicious, this could allow attackers to execute arbitrary code, potentially leading to privilege escalation or persistent access within the environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0078
The analytic detects modifications to files with extensions commonly associated with ransomware. It leverages the Endpoint.Filesystem data model to identify changes in file extensions that match known ransomware patterns. This activity is significant because it suggests an attacker is attempting to encrypt or alter files, potentially leading to severe data loss and operational disruption. If confirmed malicious, this activity could result in the encryption of critical data, rendering it inaccessible and causing significant damage to the organization's data integrity and availability.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1184
The following analytic detects MSIExec making network connections over ports 443 or 80. This behavior is identified by correlating process creation events from Endpoint Detection and Response (EDR) agents with network traffic logs. Typically, MSIExec does not perform network communication to the internet, making this activity unusual and potentially indicative of malicious behavior. If confirmed malicious, an attacker could be using MSIExec to download or communicate with external servers, potentially leading to data exfiltration, command and control (C2) communication, or further malware deployment.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
This analytic detects the creation of URL shortcut files (.url) outside of common, legitimate directories. Such activity is often associated with malware, including ransomware like CHAOS. Malicious .url files can be used to trick users into visiting harmful websites or, if placed in specific locations (e.g., Windows Startup folder), can achieve persistence and execute malicious code upon system reboot, leading to system compromise and data loss.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
2049
The following analytic identifies modifications to registry keys commonly used for persistence mechanisms. It leverages data from endpoint detection sources like Sysmon or Carbon Black, focusing on specific registry paths known to initiate applications or services during system startup. This activity is significant as unauthorized changes to these keys can indicate attempts to maintain persistence or execute malicious actions upon system boot. If confirmed malicious, this could allow attackers to achieve persistent access, execute arbitrary code, or maintain control over compromised systems, posing a severe threat to system integrity and security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0046
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