Detections

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

12,583 detections

Detects a potential webshell being executed on linux server. Follow process tree of shell commands.
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Richard Kohler@djrk01
Dtex DF
15 days ago
002
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
18 days ago
505
Hunts for sqlservr.exe spawning command shells or system utilities, a pattern consistent with xp_cmdshell abuse. It also flags later steps from a public intrusion write-up: certutil decoding, SAM, SYSTEM or SECURITY hive saves and local account or group changes.

Results are grouped per device and day and ranked by stage count. Rows can also appear without a SQL parent when two later stages occur on the same device and day.

Triage: Some jobs use xp_cmdshell legitimately. Review the command line and the account. Hunting query, not an alert.

Limitations: Activity inside the SQL process with no child process is not visible. Renamed tools, obfuscation and privilege escalation tools are not covered. Needs Defender for Endpoint on the SQL servers.
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Goksel Atakan@gokselatakan
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Hunters
18 days ago
105
Detects creation of sitecustomize.py, usercustomize.py, or .pth path configuration files inside a site-packages or dist-packages directory by a python or pip process. These files are automatically loaded by Python's site module on every subsequent interpreter start, allowing a malicious package installer to establish persistence that re-executes on every future Python invocation without further victim interaction.
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Georg Lauenstein@gsec
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SecOps Signals
13 days ago
101
Detects schtasks.exe creating a scheduled task named "Windows Defender Advanced Threat Protection Service" that launches defender.exe (a renamed Sangfor executable abused for DLL sideloading) with SYSTEM privileges at startup. This is the exact persistence mechanism HoneyMyte (Mustang Panda) uses to relaunch the CoolClient backdoor chain from the fake "Microsoft\Windows Defender" directory on every boot.
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Georg Lauenstein@gsec
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SecOps Signals
13 days ago
001
Detects creation of a JSP/JSPX/WAR server-side script inside
an AhsayCBS installation or web application directory. In this campaign the
actors exploited critical AhsayCBS vulnerabilities and dropped webshells into
the application web directories to maintain persistent remote access. Legitimate
deployment writes scripts from the AhsayCBS updater, not ad-hoc into web roots.
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Georg Lauenstein@gsec
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SecOps Signals
13 days ago
001
Detects an Entra 'Add device' event within 2 minutes after a successful sign-in from an IP never seen for that user in the lookback window, and where the registration originates from that same new IP (rogue device persistence after token replay).
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Arnold Chan@slaz
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Hunters
19 days ago
206
Detects scenarios where a user's password is reset or sessions are revoked in Azure Active Directory, followed closely by mailbox access (items accessed, sent, or deleted) from a client IP address that was never seen interacting with that mailbox prior to the password reset event.
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
13 days ago
101
An account was unlocked and then authenticated from the same IP as the account that unlocked it
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
14 days ago
001
A privileged SAP account attempted logons across multiple systems or clients from a single source IP address within a 6-hour window, potentially indicating credential compromise or lateral movement.
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Google SecOps@GoogleSecOps
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Google SecOps Detection Rules
14 days ago
001
This detection flags a parent and child process pair on internet-facing Windows servers, where the parent is a web server process and the child is the process it launched. The web server processes covered are w3wp, httpd, nginx and Tomcat, including versioned Tomcat service executables such as tomcat9.exe and Tomcat running under java.exe, which is identified by the Catalina bootstrap class in its command line. A server is treated as internet-facing based on the most recent status recorded for it.

Instead of matching known web shell names, the query builds a baseline from the previous 30 days of process activity on each device and alerts when a pair appears in the latest window that has never been seen on that device before, so it can catch web shell activity it has never seen before. Because the baseline is held per device, a pair that is normal on one server does not hide the same pair appearing on another.

The rule runs every 24 hours, as this is the only Defender custom detection frequency with a 30-day lookback, and the alert window covers the last 25 hours so that a slightly delayed run does not leave a gap.

The baseline and alert windows are separated by ingestion time rather than event time, so events that arrive late are still evaluated.
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Christopher Scott@Scocha
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Detections.ai Community
16 days ago
102
The following analytic detects modifications to the Windows registry aimed at disabling the Registry Editor (regedit). It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableRegistryTools" with a value of "0x00000001". This activity is significant because malware, such as RATs or trojans, often disable registry tools to prevent the removal of their entries, aiding in persistence and defense evasion. If confirmed malicious, this could hinder incident response efforts and allow the attacker to maintain control over the compromised system.
Splunk Security@SplunkSecurity
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Splunk Security Content
18 days ago
004
The following analytic detects suspicious registry modifications aimed at disabling Windows Group Policy features. It leverages data from the Endpoint.Registry data model, focusing on specific registry paths and values associated with disabling key Windows functionalities. This activity is significant because it is commonly used by ransomware to hinder mitigation and forensic response efforts. If confirmed malicious, this behavior could severely impair the ability of security teams to analyze and respond to the attack, allowing the attacker to maintain control and persist within the compromised environment.
Splunk Security@SplunkSecurity
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Splunk Security Content
18 days ago
004
The following analytic detects a modification to the Windows registry setting "LongPathsEnabled," which allows file paths longer than 260 characters. This detection leverages data from the Endpoint.Registry datamodel, focusing on changes to the specific registry path and value. This activity is significant because adversaries, including malware like BlackByte, exploit this setting to bypass file path limitations, potentially aiding in evasion techniques. If confirmed malicious, this modification could facilitate the execution of long-path payloads, aiding in persistence and further system compromise.
Splunk Security@SplunkSecurity
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Splunk Security Content
18 days ago
004
Behavioral hunt for accounts whose non-interactive sign-ins over 30 days are dominated (>=95%) by a single IP using a scripted client (python/aiohttp/httpx/urllib) with no browser. Scripted now requires BOTH no browser AND a scripted user agent, and Microsoft ASN egress is excluded.
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Arnold Chan@slaz
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Midnight Slayer
19 days ago
005
Behavioral hunt for accounts whose non-interactive sign-ins over 30 days are dominated (>=95%) by a single IP using a scripted client (python/aiohttp/httpx/urllib) with no browser. Scripted now requires BOTH no browser AND a scripted user agent, and Microsoft ASN egress is excluded.
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Arnold Chan@slaz
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Detection & Hunting Community
19 days ago
005
Detects an Entra 'Add device' event within 2 minutes after a successful sign-in from an IP never seen for that user in the lookback window, and where the registration originates from that same new IP (rogue device persistence after token replay).
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Arnold Chan@slaz
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Detection & Hunting Community
19 days ago
005
The following analytic detects the creation of files in the Windows %startup% folder, a common persistence technique. It leverages the Endpoint.Filesystem data model to identify file creation events in this specific directory. This activity is significant because adversaries often use the startup folder to ensure their malicious code executes automatically upon system boot or user logon. If confirmed malicious, this could allow attackers to maintain persistence on the host, potentially leading to further system compromise and unauthorized access to sensitive information.
Splunk Security@SplunkSecurity
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Splunk Security Content
12 days ago
000
Detects anomalous sign-in activity for users by comparing current successful login attempts against a 14-day historical baseline. The rule flags logins originating from new IP addresses, new applications, or new geographic locations, specifically identifying instances where at least two of these parameters deviate from the established historical norm for the specific user.
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Shadows VMB@Vemorian_Mort
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Detections.ai Community
24 days ago
9019
Detects file creation or modification events targeting specific Google Chrome extension paths, specifically involving known extension IDs associated with malicious activity or unauthorized modifications.
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ills3c Intel&Coffee@Ills3C
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Detections.ai Community
15 days ago
001
This rule detects potential persistence attempts by monitoring for the creation of suspicious registry values (common autostart locations) or new files in the Windows Startup directory. It flags registry value data or file names that match known suspicious patterns (e.g., PowerShell, cmd, temp/appdata paths, URLs) when executed by processes other than trusted installers.
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Shadows VMB@Vemorian_Mort
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Detections.ai Community
23 days ago
8011
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