Update v8.18.11
editUpdate v8.18.11
editThis section lists all updates associated with version 8.18.11 of the Fleet integration Prebuilt Security Detection Rules.
| Rule | Description | Status | Version |
|---|---|---|---|
Potential Widespread Malware Infection Across Multiple Hosts |
This rule uses alert data to determine when a malware signature is triggered in multiple hosts. Analysts can use this to prioritize triage and response, as this can potentially indicate a widespread malware infection. |
update |
4 |
Identifies when a single AWS resource is making |
update |
5 |
|
Detects when a single AWS resource is running multiple |
update |
3 |
|
Identifies when a single AWS resource is making |
update |
4 |
|
Identifies AWS EC2 EBS snaphots being shared with another AWS account or made public. EBS virtual disks can be copied into snapshots, which can then be shared with an external AWS account or made public. Adversaries may attempt this in order to copy the snapshot into an environment they control, to access the data. |
update |
7 |
|
Identifies a high number of failed S3 operations from a single source and account (or anonymous account) within a short timeframe. This activity can be indicative of attempting to cause an increase in billing to an account for excessive random operations, cause resource exhaustion, or enumerating bucket names for discovery. |
update |
5 |
|
Identifies the removal of access permissions from a shared AWS EC2 EBS snapshot. EBS snapshots are essential for data retention and disaster recovery. Adversaries may revoke or modify snapshot permissions to prevent legitimate users from accessing backups, thereby obstructing recovery efforts after data loss or destructive actions. This tactic can also be used to evade detection or maintain exclusive access to critical backups, ultimately increasing the impact of an attack and complicating incident response. |
update |
2 |
|
Identifies potential ransomware note being uploaded to an AWS S3 bucket. This rule detects the |
update |
6 |
|
Identifies |
update |
6 |
|
This rule detects when a JavaScript file is uploaded or accessed in an S3 static site directory ( |
update |
2 |
|
This rule identifies potentially suspicious activity by detecting instances where a single IAM user’s temporary session token is accessed from multiple IP addresses within a short time frame. Such behavior may suggest that an adversary has compromised temporary credentials and is utilizing them from various locations. To enhance detection accuracy and minimize false positives, the rule incorporates criteria that evaluate unique IP addresses, user agents, cities, and networks. These additional checks help distinguish between legitimate distributed access patterns and potential credential misuse. Detected activities are classified into different types based on the combination of unique indicators, with each classification assigned a fidelity score reflecting the likelihood of malicious behavior. High fidelity scores are given to patterns most indicative of threats, such as multiple unique IPs, networks, cities, and user agents. Medium and low fidelity scores correspond to less severe patterns, enabling security teams to effectively prioritize alerts. |
update |
102 |
|
Identifies when a federated user logs into the AWS Management Console without using multi-factor authentication (MFA). Federated users are typically given temporary credentials to access AWS services. If a federated user logs into the AWS Management Console without using MFA, it may indicate a security risk, as MFA adds an additional layer of security to the authentication process. This could also indicate the abuse of STS tokens to bypass MFA requirements. |
update |
4 |
|
Detects when an AWS IAM login profile is added to a root user account and is self-assigned. Adversaries, with temporary access to the root account, may add a login profile to the root user account to maintain access even if the original access key is rotated or disabled. |
update |
3 |
|
An adversary with access to a set of compromised credentials may attempt to persist or escalate privileges by attaching additional permissions to user groups the compromised user account belongs to. This rule looks for use of the IAM |
update |
6 |
|
An adversary with access to a set of compromised credentials may attempt to persist or escalate privileges by attaching additional permissions to compromised IAM roles. This rule looks for use of the IAM |
update |
6 |
|
An adversary with access to a set of compromised credentials may attempt to persist or escalate privileges by attaching additional permissions to compromised user accounts. This rule looks for use of the IAM |
update |
7 |
|
AWS Bedrock Invocations without Guardrails Detected by a Single User Over a Session |
Identifies multiple AWS Bedrock executions in a one minute time window without guardrails by the same user in the same account over a session. Multiple consecutive executions implies that a user may be intentionally attempting to bypass security controls, by not routing the requests with the desired guardrail configuration in order to access sensitive information, or possibly exploit a vulnerability in the system. |
update |
3 |
AWS Bedrock Guardrails Detected Multiple Violations by a Single User Over a Session |
Identifies multiple violations of AWS Bedrock guardrails by the same user in the same account over a session. Multiple violations implies that a user may be intentionally attempting to cirvumvent security controls, access sensitive information, or possibly exploit a vulnerability in the system. |
update |
6 |
AWS Bedrock Guardrails Detected Multiple Policy Violations Within a Single Blocked Request |
Identifies multiple violations of AWS Bedrock guardrails within a single request, resulting in a block action, increasing the likelihood of malicious intent. Multiple violations implies that a user may be intentionally attempting to cirvumvent security controls, access sensitive information, or possibly exploit a vulnerability in the system. |
update |
5 |
Detects repeated high-confidence BLOCKED actions coupled with specific Content Filter policy violation having codes such as MISCONDUCT, HATE, SEXUAL, INSULTS', PROMPT_ATTACK, VIOLENCE indicating persistent misuse or attempts to probe the model’s ethical boundaries. |
update |
7 |
|
Potential Abuse of Resources by High Token Count and Large Response Sizes |
Detects potential resource exhaustion or data breach attempts by monitoring for users who consistently generate high input token counts, submit numerous requests, and receive large responses. This behavior could indicate an attempt to overload the system or extract an unusually large amount of data, possibly revealing sensitive information or causing service disruptions. |
update |
5 |
AWS Bedrock Detected Multiple Attempts to use Denied Models by a Single User |
Identifies multiple successive failed attempts to use denied model resources within AWS Bedrock. This could indicated attempts to bypass limitations of other approved models, or to force an impact on the environment by incurring exhorbitant costs. |
update |
5 |
Unusual High Denied Sensitive Information Policy Blocks Detected |
Detects repeated compliance violation BLOCKED actions coupled with specific policy name such as sensitive_information_policy, indicating persistent misuse or attempts to probe the model’s denied topics. |
update |
3 |
Detects repeated compliance violation BLOCKED actions coupled with specific policy name such as topic_policy, indicating persistent misuse or attempts to probe the model’s denied topics. |
update |
3 |
|
AWS Bedrock Detected Multiple Validation Exception Errors by a Single User |
Identifies multiple validation exeception errors within AWS Bedrock. Validation errors occur when you run the InvokeModel or InvokeModelWithResponseStream APIs on a foundation model that uses an incorrect inference parameter or corresponding value. These errors also occur when you use an inference parameter for one model with a model that doesn’t have the same API parameter. This could indicate attempts to bypass limitations of other approved models, or to force an impact on the environment by incurring exhorbitant costs. |
update |
5 |
Detects repeated compliance violation BLOCKED actions coupled with specific policy name such as word_policy, indicating persistent misuse or attempts to probe the model’s denied topics. |
update |
3 |
|
Microsoft Entra ID Concurrent Sign-Ins with Suspicious Properties |
Identifies concurrent azure signin events for the same user and from multiple sources, and where one of the authentication event has some suspicious properties often associated to DeviceCode and OAuth phishing. Adversaries may steal Refresh Tokens (RTs) via phishing to bypass multi-factor authentication (MFA) and gain unauthorized access to Azure resources. |
update |
2 |
Identifies brute force attempts against Azure Entra multi-factor authentication (MFA) Time-based One-Time Password (TOTP) verification codes. This rule detects high frequency failed TOTP code attempts for a single user in a short time-span with a high number of distinct session IDs. Adversaries may programmatically attemopt to brute-force TOTP codes by generating several sessions and attempt to guess the correct code. |
update |
4 |
|
Identifies excessive secret or key retrieval operations from Azure Key Vault. This rule detects when a user principal retrieves secrets or keys from Azure Key Vault multiple times within a short time frame, which may indicate potential abuse or unauthorized access attempts. The rule focuses on high-frequency retrieval operations that deviate from normal user behavior, suggesting possible credential harvesting or misuse of sensitive information. |
update |
2 |
|
Identifies potential brute-force attacks targeting user accounts by analyzing failed sign-in patterns in Microsoft Entra ID Sign-In Logs. This detection focuses on a high volume of failed interactive or non-interactive authentication attempts within a short time window, often indicative of password spraying, credential stuffing, or password guessing. Adversaries may use these techniques to gain unauthorized access to applications integrated with Entra ID or to compromise valid user accounts. |
update |
4 |
|
Identifies a high count of failed Microsoft Entra ID sign-in attempts as the result of the target user account being locked out. Adversaries may attempt to brute-force user accounts by repeatedly trying to authenticate with incorrect credentials, leading to account lockouts by Entra ID Smart Lockout policies. |
update |
2 |
|
Identifies potential brute-force attacks targeting Microsoft 365 user accounts by analyzing failed sign-in patterns in Microsoft Entra ID Sign-In Logs. This detection focuses on a high volume of failed interactive or non-interactive authentication attempts within a short time window, often indicative of password spraying, credential stuffing, or password guessing. Adversaries may use these techniques to gain unauthorized access to Microsoft 365 services such as Exchange Online, SharePoint, or Teams. |
update |
106 |
|
Microsoft Entra ID Session Reuse with Suspicious Graph Access |
Identifies potential session hijacking or token replay in Microsoft Entra ID. This rule detects cases where a user signs in and subsequently accesses Microsoft Graph from a different IP address using the same session ID within a short time window. This may indicate the use of a stolen refresh/access token or session cookie to impersonate the user and interact with Microsoft services. |
update |
3 |
Identifies separate OAuth authorization flows in Microsoft Entra ID where the same user principal and session ID are observed across multiple IP addresses within a 5-minute window. These flows involve the Microsoft Authentication Broker (MAB) as the client application and the Device Registration Service (DRS) as the target resource. This pattern is highly indicative of OAuth phishing activity, where an adversary crafts a legitimate Microsoft login URL to trick a user into completing authentication and sharing the resulting authorization code, which is then exchanged for an access and refresh token by the attacker. |
update |
3 |
|
Detects a change to the OpenID Connect (OIDC) discovery URL in the Entra ID Authentication Methods Policy. This behavior may indicate an attempt to federate Entra ID with an attacker-controlled identity provider, enabling bypass of multi-factor authentication (MFA) and unauthorized access through bring-your-own IdP (BYOIDP) methods. |
update |
3 |
|
Detects patterns indicative of Denial-of-Service (DoS) attacks on machine learning (ML) models, focusing on unusually high volume and frequency of requests or patterns of requests that are known to cause performance degradation or service disruption, such as large input sizes or rapid API calls. |
update |
3 |
|
Detects when Azure OpenAI requests result in zero response length, potentially indicating issues in output handling that might lead to security exploits such as data leaks or code execution. This can occur in cases where the API fails to handle outputs correctly under certain input conditions. |
update |
3 |
|
Monitors for suspicious activities that may indicate theft or unauthorized duplication of machine learning (ML) models, such as unauthorized API calls, atypical access patterns, or large data transfers that are unusual during model interactions. |
update |
3 |
|
Identifies when an excessive number of files are downloaded from OneDrive using OAuth authentication. Adversaries may conduct phishing campaigns to steal OAuth tokens and impersonate users. These access tokens can then be used to download files from OneDrive. |
update |
3 |
|
Multiple Microsoft 365 User Account Lockouts in Short Time Window |
Detects a burst of Microsoft 365 user account lockouts within a short 5-minute window. A high number of IdsLocked login errors across multiple user accounts may indicate brute-force attempts for the same users resulting in lockouts. |
update |
3 |
Identifies brute-force authentication activity targeting Microsoft 365 user accounts using failed sign-in patterns that match password spraying, credential stuffing, or password guessing behavior. Adversaries may attempt brute-force authentication with credentials obtained from previous breaches, leaks, marketplaces or guessable passwords. |
update |
414 |
|
Identifies sign-ins on behalf of a principal user to the Microsoft Graph API from multiple IPs using the Microsoft Authentication Broker or Visual Studio Code application. This behavior may indicate an adversary using a phished OAuth refresh token. |
update |
3 |
|
This rule detects when a specific Okta actor has multiple device token hashes for a single Okta session. This may indicate an authenticated session has been hijacked or is being used by multiple devices. Adversaries may hijack a session to gain unauthorized access to Okta admin console, applications, tenants, or other resources. |
update |
307 |
|
Multiple Okta User Authentication Events with Client Address |
Detects when a certain threshold of Okta user authentication events are reported for multiple users from the same client address. Adversaries may attempt to launch a credential stuffing or password spraying attack from the same device by using a list of known usernames and passwords to gain unauthorized access to user accounts. |
update |
206 |
Multiple Okta User Authentication Events with Same Device Token Hash |
Detects when a high number of Okta user authentication events are reported for multiple users in a short time frame. Adversaries may attempt to launch a credential stuffing or password spraying attack from the same device by using a list of known usernames and passwords to gain unauthorized access to user accounts. |
update |
206 |
High Number of Okta Device Token Cookies Generated for Authentication |
Detects when an Okta client address has a certain threshold of Okta user authentication events with multiple device token hashes generated for single user authentication. Adversaries may attempt to launch a credential stuffing or password spraying attack from the same device by using a list of known usernames and passwords to gain unauthorized access to user accounts. |
update |
206 |
Detects when a specific Okta actor has multiple sessions started from different geolocations. Adversaries may attempt to launch an attack by using a list of known usernames and passwords to gain unauthorized access to user accounts from different locations. |
update |
307 |
|
High Number of Egress Network Connections from Unusual Executable |
This rule detects a high number of egress network connections from an unusual executable on a Linux system. This could indicate a command and control (C2) communication attempt, a brute force attack via a malware infection, or other malicious activity. ESQL rules have limited fields available in its alert documents. Make sure to review the original documents to aid in the investigation of this alert. |
update |
5 |
This rule leverages ESQL to detect unusual base64 encoding/decoding activity on Linux systems. Attackers may use base64 encoding/decoding to obfuscate data, such as command and control traffic or payloads, to evade detection by host- or network-based security controls. ESQL rules have limited fields available in its alert documents. Make sure to review the original documents to aid in the investigation of this alert. |
update |
5 |
|
This rule detects potential port scanning activity from a compromised host. Port scanning is a common reconnaissance technique used by attackers to identify open ports and services on a target system. A compromised host may exhibit port scanning behavior when an attacker is attempting to map out the network topology, identify vulnerable services, or prepare for further exploitation. This rule identifies potential port scanning activity by monitoring network connection attempts from a single host to a large number of ports within a short time frame. ESQL rules have limited fields available in its alert documents. Make sure to review the original documents to aid in the investigation of this alert. |
update |
5 |
|
This rule detects potential subnet scanning activity from a compromised host. Subnet scanning is a common reconnaissance technique used by attackers to identify live hosts within a network range. A compromised host may exhibit subnet scanning behavior when an attacker is attempting to map out the network topology, identify vulnerable hosts, or prepare for further exploitation. This rule identifies potential subnet scanning activity by monitoring network connection attempts from a single host to a large number of hosts within a short time frame. ESQL rules have limited fields available in its alert documents. Make sure to review the original documents to aid in the investigation of this alert. |
update |
5 |
|
This rule leverages ESQL to detect the execution of unusual file transfer utilities on Linux systems. Attackers may use these utilities to exfiltrate data from a compromised system. ESQL rules have limited fields available in its alert documents. Make sure to review the original documents to aid in the investigation of this alert. |
update |
5 |
|
This detection identifies a Linux host that has potentially been infected with malware and is being used to conduct brute-force attacks against external systems over SSH (port 22 and common alternative SSH ports). The detection looks for a high volume of outbound connection attempts to non-private IP addresses from a single process. A compromised host may be part of a botnet or controlled by an attacker, attempting to gain unauthorized access to remote systems. This behavior is commonly observed in SSH brute-force campaigns where malware hijacks vulnerable machines to expand its attack surface. ESQL rules have limited fields available in its alert documents. Make sure to review the original documents to aid in the investigation of this alert. |
update |
5 |
|
This rule detects unusual processes spawned from a web server parent process by identifying low frequency counts of process spawning activity. Unusual process spawning activity may indicate an attacker attempting to establish persistence, execute malicious commands, or establish command and control channels on the host system. ESQL rules have limited fields available in its alert documents. Make sure to review the original documents to aid in the investigation of this alert. |
update |
5 |
|
This rule detects potential command execution from a web server parent process on a Linux host. Adversaries may attempt to execute commands from a web server parent process to blend in with normal web server activity and evade detection. This behavior is commonly observed in web shell attacks where adversaries exploit web server vulnerabilities to execute arbitrary commands on the host. The detection rule identifies unusual command execution from web server parent processes, which may indicate a compromised host or an ongoing attack. ESQL rules have limited fields available in its alert documents. Make sure to review the original documents to aid in the investigation of this alert. |
update |
5 |
|
Generates a detection alert for each Elastic Security alert written to the configured indices. Enabling this rule allows you to immediately begin investigating Elastic Security alerts in the app. |
update |
2 |
|
Identifies rare connection attempts to a Web Distributed Authoring and Versioning (WebDAV) resource. Attackers may inject WebDAV paths in files or features opened by a victim user to leak their NTLM credentials via forced authentication. |
update |
2 |
|
Potential PowerShell Obfuscation via Invalid Escape Sequences |
Identifies PowerShell scripts that use invalid escape sequences as a form of obfuscation. This technique introduces backticks (`) between characters in a way that does not correspond to valid PowerShell escape sequences, breaking up strings and bypassing pattern-based detections while preserving execution logic. This is designed to evade static analysis and bypass security protections such as the Antimalware Scan Interface (AMSI). |
update |
4 |
Potential PowerShell Obfuscation via Backtick-Escaped Variable Expansion |
Identifies PowerShell scripts that use backtick-escaped characters inside ${} variable expansion as a form of obfuscation. These methods are designed to evade static analysis and bypass security protections such as the Antimalware Scan Interface (AMSI). |
update |
3 |
Potential PowerShell Obfuscation via Character Array Reconstruction |
Identifies PowerShell scripts that use character arrays and runtime string reconstruction as a form of obfuscation. This technique breaks strings into individual characters, often using constructs like char[] with index-based access or joining logic. These methods are designed to evade static analysis and bypass security protections such as the Antimalware Scan Interface (AMSI). |
update |
3 |
Potential PowerShell Obfuscation via Concatenated Dynamic Command Invocation |
Identifies PowerShell scripts that use concatenated strings within dynamic command invocation (&() or .()) as a form of obfuscation. These methods are designed to evade static analysis and bypass security protections such as the Antimalware Scan Interface (AMSI). |
update |
3 |
Potential PowerShell Obfuscation via High Numeric Character Proportion |
Identifies PowerShell scripts with a disproportionately high number of numeric characters, often indicating the presence of obfuscated or encoded payloads. This behavior is typical of obfuscation methods involving byte arrays, character code manipulation, or embedded encoded strings used to deliver and execute malicious content. |
update |
4 |
Potential Dynamic IEX Reconstruction via Environment Variables |
Identifies PowerShell scripts that reconstruct the IEX (Invoke-Expression) command at runtime using indexed slices of environment variables. This technique leverages character access and join operations to build execution logic dynamically, bypassing static keyword detection and evading defenses such as AMSI. |
update |
3 |
Identifies PowerShell scripts that reconstruct the IEX (Invoke-Expression) command by accessing and indexing the string representation of method references. This obfuscation technique uses constructs like ''.IndexOf.ToString() to expose method metadata as a string, then extracts specific characters through indexed access and joins them to form IEX, bypassing static keyword detection and evading defenses such as AMSI. |
update |
4 |
|
Identifies PowerShell scripts that use negative index ranges to reverse the contents of a string or array at runtime as a form of obfuscation. This technique avoids direct use of reversal functions by iterating through array elements in reverse order. These methods are designed to evade static analysis and bypass security protections such as the Antimalware Scan Interface (AMSI). |
update |
3 |
|
Identifies PowerShell scripts that use reversed strings as a form of obfuscation. These methods are designed to evade static analysis and bypass security protections such as the Antimalware Scan Interface (AMSI). |
update |
3 |
|
Identifies PowerShell scripts that use string concatenation as a form of obfuscation. These methods are designed to evade static analysis and bypass security protections such as the Antimalware Scan Interface (AMSI). |
update |
4 |
|
Identifies PowerShell scripts that use string reordering and runtime reconstruction techniques as a form of obfuscation. These methods are designed to evade static analysis and bypass security protections such as the Antimalware Scan Interface (AMSI). |
update |
5 |
|
Potential PowerShell Obfuscation via Special Character Overuse |
Identifies PowerShell scripts with an unusually high proportion of whitespace and special characters, often indicative of obfuscation. This behavior is commonly associated with techniques such as SecureString encoding, formatting obfuscation, or character-level manipulation designed to bypass static analysis and AMSI inspection. |
update |
4 |
Identifies PowerShell script blocks associated with multiple distinct detections, indicating likely malicious behavior. |
update |
2 |