Detections

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

2,294 detections

The following analytic detects the use of the Windows binary attrib.exe to hide files or directories by marking them with specific flags. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line arguments that include the "+h" flag. This activity is significant because hiding files can be a tactic used by attackers to conceal malicious files or tools from users and security software. If confirmed malicious, this behavior could allow an attacker to persist in the environment undetected, potentially leading to further compromise or data exfiltration.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1036
This query was originally published in the threat analytics report, CVE-2020-0601 certificate validation vulnerability.
The Windows CryptoAPI Spoofing Vulnerability, CVE-2020-0601, can be exploited to spoof code-signing certificates. For example, an attacker could forge a certificate that lists Microsoft as the issuer. This would allow an attacker to disguise a malicious executable as legitimate.
The vulnerability was patched with the January 2020 Security Update.
Use the following query to locate files containing ECC certificates that might have been forged using this vulnerability. The query identifies files that don't correctly identify the signer name, yet list Microsoft as the root signer.
References:
https://portal.msrc.microsoft.com/security-guidance/advisory/CVE-2020-0601
https://portal.msrc.microsoft.com/security-guidance/releasenotedetail/2020-Jan
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0034
Directly prior to deploying Macaw ransomware in an organization, the attacker will run several commands designed to disable security tools and system recovery tools.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0033
Search for the files that are using a compromised certificate associated with the Nobelium campaign.
You can remove the comments to:
1. get the list of devices where there is at least one file signed with the certificate
2. get the list of files signed with the certificate
3. get the list of files signed with the certificate group by Devices
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0031
'Dev-0530 actors are known to encrypt the contents of the victims device as well as renaming the file extensions. This query looks for the creation of files with .h0lyenc extension or presence of ransom note.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
6022
This query was originally published in the threat analytics report, Adwind utilizes Java for cross-platform impact.
Adwind is a remote access tool (RAT) that takes advantage of the cross-platform capabilities of the Java framework. It can check which operating system a target is running and adapt accordingly, allowing it to successfully compromise both Windows and macOS devices.
The query below checks for attempts to disguise Java class files (i.e., complied code with a .class extension). Although the behavior detected by this query is typical of attacks that use Adwind malware, unrelated attacks may use the same or similar defense evasion techniques.
See Detecting a JAR attachment for an additional query that detects behavior associated with Adwind attacks.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0021
This query was originally published in the threat analytics report, ALPC local privilege elevation.
Windows ALPC Elevation of Privilege Vulnerability, CVE-2018-8440, could be exploited to run arbitrary code or to gain access to protected directories and areas of the operating system.
This vulnerability was patched in the September 2018 Security Update.
The following query checks for potential activity related to this vulnerability over the past 7 days. If you wish to check another time period, update the EventTime value.
References:
https://nvd.nist.gov/vuln/detail/CVE-2018-8440
https://support.microsoft.com/help/4457143/windows-81-update-kb4457143
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0017
Look for the creation of suspicious DLL files spawned in the \spool\ folder along with DLLs that were recently loaded afterwards from \Old.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0016
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
This query is looking for rarely seen processes which are launched as a service.
Author: Jouni Mikkola
More info: https://threathunt.blog/rare-process-launch-as-a-service/
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2014
The analytic detects potential access or modification of the /etc/sudoers file on a Linux system. It leverages data from Linux Auditd, focusing on processes like "cat," "nano," "vim," and "vi" accessing the /etc/sudoers file. This activity is significant because the sudoers file controls user permissions for executing commands with elevated privileges. If confirmed malicious, an attacker could gain persistence or escalate privileges, compromising the security of the targeted host.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0045
The analytic detects suspicious access or modification of the sshd_config file on Linux systems. It leverages data from Linux Auditd, focusing on command-line executions involving processes like "cat," "nano," "vim," and "vi" accessing the sshd_config file. This activity is significant because unauthorized changes to sshd_config can allow threat actors to redirect port connections or use unauthorized keys, potentially compromising the system. If confirmed malicious, this could lead to unauthorized access, privilege escalation, or persistent backdoor access, posing a severe security risk.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0032
The following analytic detects potential tampering with cronjob files on a Linux system by identifying 'echo' commands that append code to existing cronjob files. It leverages logs from Linux Auditd, focusing on process names, parent processes, and command-line executions. This activity is significant because adversaries often use it for persistence or privilege escalation. If confirmed malicious, this could allow attackers to execute unauthorized code automatically, leading to system compromises and unauthorized data access, thereby impacting business operations and data integrity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0031
The following analytic detects suspicious preload hijacking via the `preload` file, which may indicate an attacker's attempt to intercept or manipulate library loading processes. The `preload` file can be used to force the loading of specific libraries before others, potentially allowing malicious code to execute or alter application behavior. By monitoring for unusual or unauthorized modifications to the `preload` file, this analytic helps identify attempts to hijack preload mechanisms, enabling security teams to investigate and address potential threats to system integrity and security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0028
This rule detects attempts to create or rename files with a space at the end of their filename, which can be used to obfuscate malicious files or commands. Specifically, it looks for command-line executions involving 'echo "*" > * && chmod +x *' or 'mv * "* "'. The first pattern suggests creating an executable file with a trailing space, and the second suggests renaming a file to include a trailing space.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
0020
Detects the potential abuse of the Linux Magic SysRq (System Request) key by adversaries with root or sufficient privileges to silently manipulate or destabilize a system. By writing to /proc/sysrq-trigger, they can crash the system, kill processes, or disrupt forensic analysis—all while bypassing standard logging. Though intended for recovery and debugging, SysRq can be misused as a stealthy post-exploitation tool. It is controlled via /proc/sys/kernel/sysrq or permanently through /etc/sysctl.conf.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
2025
The following analytic detects the creation of files typically associated with SharpHound, a reconnaissance tool used for gathering domain and trust data. It leverages file modification events from the Endpoint.Filesystem data model, focusing on default file naming patterns like `*_BloodHound.zip` and various JSON files. This activity is significant as it indicates potential domain enumeration, which is a precursor to more targeted attacks. If confirmed malicious, an attacker could gain detailed insights into the domain structure, facilitating lateral movement and privilege escalation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1082
The following analytic detects the usage of the `plutil` command to modify plist files on macOS systems. It leverages osquery to monitor process events, specifically looking for executions of `/usr/bin/plutil`. This activity is significant because adversaries can use `plutil` to alter plist files, potentially adding malicious binaries or command-line arguments that execute upon user logon or system startup. If confirmed malicious, this could allow attackers to achieve persistence, execute arbitrary code, or escalate privileges, posing a significant threat to the system's security.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
1059
The analytic detects the creation of specific AzureHound-related files, such as `*-azurecollection.zip` and various `.json` files, on disk. It leverages data from the Endpoint.Filesystem datamodel, focusing on file creation events with specific filenames. This activity is significant because AzureHound is a tool used to gather information about Azure environments, similar to SharpHound for on-premises Active Directory. If confirmed malicious, this activity could indicate an attacker is collecting sensitive Azure environment data, potentially leading to further exploitation or privilege escalation within the cloud infrastructure.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0055
This analytic detects suspicious command-lines that modify user profile files to automatically execute scripts or executables upon system reboot. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving profile files like ~/.bashrc and /etc/profile. This activity is significant as it indicates potential persistence mechanisms used by adversaries to maintain access to compromised hosts. If confirmed malicious, this could allow attackers to execute arbitrary code upon reboot, leading to persistent control over the system and potential further exploitation.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0050
The analytic detects the addition of NOPASSWD entries to the /etc/sudoers file on Linux systems. It leverages Linux Auditd data to identify command lines containing "NOPASSWD:". This activity is significant because it allows users to execute commands with elevated privileges without requiring a password, which can be exploited by adversaries to maintain persistent, privileged access. If confirmed malicious, this could lead to unauthorized privilege escalation, persistent access, and potential compromise of sensitive data and system integrity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
7046
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