Detections

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

7,138 detections

Detects the use of the "git" utility to execute a shell. Such behavior may be associated with privilege escalation, unauthorized command execution, or to break out from restricted environments.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
Detects the use of the "nice" utility to execute a shell. Such behavior may be associated with privilege escalation, unauthorized command execution, or to break out from restricted environments.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
Detects the use of the "ssh" utility to execute a shell. Such behavior may be associated with privilege escalation, unauthorized command execution, or to break out from restricted environments.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
000
Following the September 14th, 2021 release of three Elevation of Privilege (EoP) vulnerabilities (CVE-2021-38645, CVE-2021-38649, CVE-2021-38648) and one unauthenticated Remote Code Execution (RCE) vulnerability (CVE-2021-38647) in the Open Management Infrastructure (OMI) Framework.
This detection validates that any OMS-agent that is reporting to the Microsoft Sentinel workspace is updated with the patch. The detection will go over the heartbeats received from all agents over the last day and will create alert for those agents who are not updated.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1023
'Query finds accounts recorded as disabled by AD in previous time period but still using proxy in current time period. Presumes default squid log format is used. http://www.squid-cache.org/Doc/config/access_log/'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0021
Yara rule that detects ChaosRAT backdoor.
ReversingLabs Yara@ReversingLabsYara
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ReversingLabs Yara
1 year ago
000
This query was originally published in the threat analytics report, OSX/SurfBuyer adware campaign.
It will return results if a shell script has furtively attempted to decode and save a file to a /tmp folder.
If discovered on your system, this kind of activity might be associated with SurfBuyer, which is adware that installs a browser extension to take control of several major web browsers, including Safari, Google Chrome, and Firefox.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0018
'This query uses the Azure Defender Security Nested Recommendations data to find machines vulnerable to OMIGOD CVE-2021-38647.
OMI is the Linux equivalent of Windows WMI and helps users manage configurations across remote and local environments. The query aims to find machines that have this OMI vulnerability (CVE-2021-38647).
Security Nested Recommendations data is sent to Microsoft Sentinel using the continuous export feature of Azure Defender(refrence link below).
Reference: https://www.wiz.io/blog/omigod-critical-vulnerabilities-in-omi-azure
Reference: https://docs.microsoft.com/azure/security-center/continuous-export?tabs=azure-portal'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0018
This query uses the public MDE GitHub repo as a source to estimate the time that an agent build remains supported
based on the time it was uploaded. Please note that the timestamps used in this query are meant to estimate the
support period and will likely not represent the actual expiration of the package which will be based on the build.
If you would like an estimate of support, uncomment the extend statement to get an idea of what is \ is not
supported and an idea of how long support will remain for current agents.
This query currently only supports GA builds, not preview builds.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0017
The query checks process command lines arguments and parent/child combinations to find machines where there have been.
Attempts to exploit a DHCP remote code command injection CVE-2018-1111.
DynoRoot is a remote command injection present in a script included by the DHCP client in Red Hat Enterprise Linux 6 and 7.
Using it, a malicious attacker could use this flaw to execute arbitrary commands with root privileges.
CVE: CVE-2018-1111.
Read more here:.
Https://access.redhat.com/security/cve/cve-2018-1111.
Https://www.cvedetails.com/cve/CVE-2018-1111.
Tags: #exploit #CVE-2018-1111 #DynoRoot.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0015
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
The following analytic detects the unexpected termination of the Linux Audit daemon (auditd) by monitoring for log entries of type DAEMON_END. This event signifies that the audit logging service has stopped, either due to a legitimate system shutdown, manual administrative action, or potentially malicious tampering. Since auditd is responsible for recording critical security events, its sudden stoppage may indicate an attempt to disable security monitoring or evade detection during an attack. This detection should be correlated with system logs to determine whether the shutdown was part of routine maintenance or an anomaly. If confirmed as malicious, this could lead to a compromised system where security events are no longer being logged, allowing attackers to operate undetected. Therefore, monitoring and alerting on auditd shutdown events is crucial for maintaining the integrity of system security monitoring.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0052
The following analytic detects the suspicious auditd service stop. This behavior is critical for a SOC to monitor because it may indicate attempts to gain unauthorized access or maintain control over a system. Such actions could be signs of malicious activity. If confirmed, this could lead to serious consequences, including a compromised system, unauthorized access to sensitive data, or even a wider breach affecting the entire network. Detecting and responding to these signs early is essential to prevent potential security incidents.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0051
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 following analytic detects the abnormal termination of the Linux audit daemon (auditd) by identifying DAEMON_ABORT events in audit logs. These terminations suggest a serious failure of the auditing subsystem, potentially due to resource exhaustion, corruption, or malicious interference. Unlike a clean shutdown, DAEMON_ABORT implies that audit logging may have been disabled without system administrator intent. Alerts should be generated on detection and correlated with DAEMON_START, DAEMON_END, and system logs to determine root cause. If no DAEMON_START follows soon after, or this pattern repeats, it indicates a high-severity issue that impacts log integrity and should be immediately investigated.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0044
The following analytic detects the (re)initialization of the Linux audit daemon (auditd) by identifying log entries of type DAEMON_START. This event indicates that the audit subsystem has resumed logging after being stopped or has started during system boot. While DAEMON_START may be expected during reboots or legitimate configuration changes, it can also signal attempts to re-enable audit logging after evasion, or restarts with modified or reduced rule sets. Monitoring this event in correlation with DAEMON_END, DAEMON_ABORT, and auditctl activity provides visibility into the continuity and integrity of audit logs. Frequent or unexplained DAEMON_START events should be investigated, especially if they are not accompanied by valid administrative or system activity.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0041
The following analytic detects the suspicious sysmon service stop. This behavior is critical for a SOC to monitor because it may indicate attempts to gain unauthorized access or maintain control over a system. Such actions could be signs of malicious activity. If confirmed, this could lead to serious consequences, including a compromised system, unauthorized access to sensitive data, or even a wider breach affecting the entire network. Detecting and responding to these signs early is essential to prevent potential security incidents.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0036
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
0031
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 the creation of the doas.conf file on a Linux host. This file is used by the doas utility to allow standard users to perform tasks as root, similar to sudo. The detection leverages Linux Auditd data, focusing on the creation of the doas.conf file. This activity is significant because it can indicate an attempt to gain elevated privileges, potentially by an adversary. If confirmed malicious, this could allow an attacker to execute commands with root commands with root privileges, leading to full system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0030
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