Detections

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

881 detections

This analytic detects PowerShell commands that initiate a process on a remote endpoint using the Distributed Component Object Model (DCOM) protocol. It specifically looks for the use of "ShellExecute" or "ExecuteShellCommand" within PowerShell Script Block Logging (EventCode=4104). This activity is significant as it may indicate lateral movement or remote code execution attempts by adversaries, potentially leading to further compromise and persistence within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0028
This analytic detects the execution of PowerShell commands that use the `Invoke-Command` cmdlet to start a process on a remote endpoint via the WinRM protocol. It leverages PowerShell Script Block Logging (EventCode=4104) to identify such activities. This behavior is significant as it may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this activity could allow attackers to execute arbitrary code on remote systems, potentially leading to further compromise and persistence within the network.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
0027
'Identifies a list of IP addresses with a minimum number (default of 5) of failed logon attempts to Microsoft Entra ID.
Uses that list to identify any successful remote logons to hosts from these IPs within the same timeframe.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0092
Remote Monitoring and Management (RMM) programs are IT to manage remote endpoints. Attackers have begun to abuse these programs to persist or provide C2 channels.
https://github.com/jischell-msft/RemoteManagementMonitoringTools
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
9084
'Query detects potential lateral movement within a network by identifying when an RDP connection (EventID 4624, LogonType 10) is made to an initial system, followed by a subsequent RDP connection from that system to another, using the same account within a 60-minute window.
To reduce false positives, it excludes scenarios where the same account has made 5 or more connections to the same set of computers in the previous 7 days. This approach focuses on highlighting unusual RDP behaviour that suggests lateral movement, which is often associated with attacker tactics during a network breach.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
4075
Service Accounts Performing Remote PowerShell.
Author: miflower.
The purpose behind this detection is for finding service accounts that are performing remote powershell sessions.
There are two phases to the detection: Identify service accounts, Find remote PS cmdlets being ran by these accounts.
To accomplish this, we utilize DeviceLogonEvents and DeviceEvents to find cmdlets ran that meet the criteria.
One of the main advantages of this method is that only requires server telemetry, and not the attacking client.
The first phase relies on the DeviceLogonEvents to determine whether an account is a service account or not, consider the following accounts with logons:.
Random_user has DeviceLogonEvents with type 2, 3, 7, 10, 11 & 13.
Random_service_account 'should' only have DeviceLogonEvents with type 3,4 or 5.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2063
'This query looks at correlating different reconnaissance alerts with interactive logon logs to help analysts investigate initial possible compromise activity'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0063
'Any Alerts that fired related to a given IpAddress during the range of +6h and -3d'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2042
Expanding on DeviceEvents output with Attack Surface Reduction (ASR) rule descriptions.
The ActionType values of the ASR events already explain what rule was matched and if it was audited or blocked.
However, it could still be useful to have a more human-friendly description in the results.
Also, this query is a good example for how you could define your own lookup tables and join with them.
The events in the DeviceEvents table contain a GUID for the various ASR rules rather than a full description of the rule.
This query will create a table which has the description for each ASR rule as per https://docs.microsoft.com/windows/security/threat-protection/windows-defender-exploit-guard/enable-attack-surface-reduction.
This table is then joined to the output of a query against the DeviceEvents table and shows a summary count of the events by the newly defined description.
This query shows the ability to use joins and custom dimension tables.
See https://docs.loganalytics.io/docs/Language-Reference/Tabular-operators/join-operator for more information on the join syntax.
For more questions on this query, feel free to ping @FlyingBlueMonki on twitter or mattegen@microsoft.com via email.
First lets start by creating a table of the rule descriptions to rule guids.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
4042
This query was originally published in the threat analytics report, Exploitation of CVE-2019-0708 (BlueKeep).
CVE-2019-0708, also known as BlueKeep, is a critical remote code execution vulnerability involving RDP. Soon after its disclosure, the NSA issued a rare advisory about this vulnerability, out of concern that it could be used to quickly spread malware. Attackers have since used this vulnerability to install cryptocurrency miners on targets.
Microsoft has issued updates for this vulnerability, as well as guidance for protecting operating systems that we no longer support. Microsoft Defender ATP also contains behavioral detections for defending against this threat.
The following query locates Windows 7 or Windows Server 2008 machines initiating outbound connections to internal or public IP addresses on TCP port 3389. It filters out common RDP programs and scanning tools and shows the number of connections per machine. It can identify machines with relatively intense outbound network activity on the common RDP port (TCP/3389). You can use it to find processes that might be scanning for possible targets or exhibiting worm-like behavior.
References:
https://nvd.nist.gov/vuln/detail/CVE-2019-0708
https://www.nsa.gov/News-Features/News-Stories/Article-View/Article/1865726/nsa-cybersecurity-advisory-patch-remote-desktop-services-on-legacy-versions-of/
https://www.wired.com/story/bluekeep-hacking-cryptocurrency-mining/
https://portal.msrc.microsoft.com/security-guidance/advisory/CVE-2019-0708
https://support.microsoft.com/help/4500705/customer-guidance-for-cve-2019-0708
https://www.microsoft.com/security/blog/2019/11/07/the-new-cve-2019-0708-rdp-exploit-attacks-explained/
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2039
'IP addresses of broadband links that usually indicates users attempting to access their home network, for example for a remote session to a home computer.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1037
This query was originally published in the threat analytics report, Cypherpunk ransomware leaves wake of tampered AVs.
Cypherpunk is a human-operated ransomware campaign named after the unusual .cypherpunk extension given to encrypted files.
The query below surfaces commands that follow the distinctive pattern Cypherpunk operators would use to remotely execute code.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0030
Intent:
- Use MTP capability to look for insider threat potential risk indicators
- Indicators would then serve as the building block for insider threat risk modeling in subsequent tools
Definition of Insider Threat:
"The potential for an individual who has or had authorized access to an organization's assets to use their access, either maliciously or unintentionally, to act in a way that could negatively affect the organization."
This collection of queries describes the different indicators that could be used to model and look for patterns suggesting an increased risk of an individual becoming a potential insider threat.
Note: no single indicator should be used as a lone determinant of insider threat activity, but should be part of an overall program to understand the increased risk to your organization's critical assets. This in turn is used to feed an investigation by a formal insider threat program to look at the context associated with the whole person to understand the implication of a set of indicators.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
1030
'Detects a successful logon by a privileged account from an ASN not logged in from in the last 14 days.
Monitor these logons to ensure they are legitimate and identify if there are any similar sign ins.'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0030
Remote Monitoring and Management (RMM) programs are IT to manage remote endpoints. Attackers have begun to abuse these programs to persist or provide C2 channels.
https://github.com/jischell-msft/RemoteManagementMonitoringTools
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0025
This query was originally published in the threat analytics report, "Exchange Server zero-days exploited in the wild".
In early March 2021, Microsoft released patches for four different zero-day vulnerabilities affecting Microsoft Exchange Server. The vulnerabilities were being used in a coordinated attack. For more information on the vulnerabilities, visit the following links:
1. CVE-2021-26855
2. CVE-2021-26857
3. CVE-2021-26858
4. CVE-2021-27065
The following query finds evidence of Base64-encoded commands used by the Nishang penetration testing framework to load a reverse TCP shell. This might indicate an attacker has remote access to the device.
More queries related to this threat can be found under the See also section of this page.
Reference - https://msrc-blog.microsoft.com/2021/03/02/multiple-security-updates-released-for-exchange-server/
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0024
Remote Monitoring and Management (RMM) programs are IT to manage remote endpoints. Attackers have begun to abuse these programs to persist or provide C2 channels.
https://github.com/jischell-msft/RemoteManagementMonitoringTools
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
2024
This query was originally published in the threat analytics report, Cypherpunk ransomware leaves wake of tampered AVs.
Cypherpunk is a human-operated ransomware campaign named after the unusual .cypherpunk extension given to encrypted files. The attackers often used PSEXESVC, a service that helps the PsExe.exe utility run commands on a remote device. Both PSEXESVC and PsExe.exe are legitimate parts of Windows; however, they can be repurposed by attackers to perform malicious actions.
The query below can find instances of PSEXESVC being used to launch batch files, as often occurred in Cypherpunk attacks.
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0019
This rule detects DNS queries to domains associated with legitimate remote access software (e.g., TeamViewer, Go2Assist, LogMeIn, AmmyyAdmin, RustDesk, Quick Assist, Remote Utilities, Tailscale, Twingate, NetSupport Manager) when those queries originate from a non-browser application. Adversaries often leverage these legitimate tools to establish command and control (C2) channels or maintain persistence on compromised systems, as they may be allowed by application control policies. The rule includes extensive filters to exclude common web browsers and other legitimate system processes that might legitimately query these domains, aiming to reduce false positives.
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SigmaHQ Detections@sigmaHQ
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SigmaHQ
1 year ago
4186
This rule identifies 'improbable travel' scenarios where a user successfully logs in from two geographically distant locations within a short time frame, suggesting potential account compromise or abuse, possibly related to Remote Employment Fraud (REF). It calculates the speed of travel required between consecutive login locations and flags events where the speed and distance exceed predefined thresholds. It also checks if the login country differs from the user's known work country.
Splunk Security@SplunkSecurity
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Splunk Security Content
1 year ago
20104
'The alert shows users that join a Zoom meeting from a time zone other than the one the meeting was created in.
You can also whitelist known good time zones in the tz_whitelist value using the tz database name format https://en.wikipedia.org/wiki/List_of_tz_database_time_zones'
Azure Sentinel@AzureSentinel
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AzureSentinel
1 year ago
0018
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