T1110.001 Password Guessing

This diagnostic statement implements security controls and restrictions for remote user access to systems. Remote user access control involves managing and securing how users remotely access systems, such as through encrypted connections and account use policies, which help prevent adversary access.

This diagnostic statement includes implementation of controls for third-party access to an organization’s systems. Enforcing third-party account use policies to include account lockout policies after a certain number of failed login attempts mitigates the risk of brute-force attacks.

This diagnostic statement protects against Password Guessing through the use of privileged account management and the use of multi-factor authentication.

This diagnostic statement provides protection from Brute Force through the implementation of authentication controls and privileged account management controls to limit credential access. Employing limitations to specific accounts, access control mechanisms, and auditing the attribution logs provides protection against adversaries attempting to brute force credentials.

This diagnostic statement protects against Brute Force through the use of revocation of keys and key management. Employing strong encryption keys and limitations to specific accounts along with access control mechanisms provides protection against adversaries attempting to guess credentials.

This diagnostic statement describes how the organization implement appropriate authentication requirements, including selecting mechanisms based on risk, utilizing multi-factor authentication where necessary, and safeguarding the storage of authenticators like pins and passwords to protect sensitive access credentials.

This diagnostic statement protects against Password Guessing through the use of hardened access control policies, secure defaults, password complexity requirements, multifactor authentication requirements, and removal of terminated accounts.

The "Summary of user logons by logon type" Microsoft Sentinel Hunting query compares successful and unsuccessful logon attempts to identify potential lateral movement. The following Microsoft Sentinel Hunting queries can identify potential attempts at credential brute force based on unsuccessful attempts: "VIP account more than 6 failed logons in 10", "Multiple Failed Logon on SQL Server in Short time Span", "Permutations on logon attempts by UserPrincipalNames indicating potential brute force", "Potential IIS brute force", "Failed attempt to access Azure Portal", "Failed Login Attempt by Expired account", "Failed Logon Attempts on SQL Server", "Failed Logon on SQL Server from Same IPAddress in Short time Span", "Failed service logon attempt by user account with available AuditData", "Login attempt by Blocked MFA user", "Login spike with increase failure rate", "Attempts to sign-in to disabled accounts by IP address", "Attempts to sign-in to disabled accounts by account name", "Brute Force attack against Azure Portal", and "Anomalous Failed Logon" The following Microsoft Sentinel Analytics queries can identify potential attempts at credential brute force based on unsuccessful attempts: "Brute force attack against Azure Portal", "Password spray attack against Azure AD application", "Successful logon from IP and failure from a different IP", "Failed logon attempts in authpriv", "Failed AzureAD logons but success logon to host", "Excessive Windows logon failures", "Failed login attempts to Azure Portal", "Failed logon attempts by valid accounts within 10 mins", "Brute Force Attack against GitHub Account", "Distributed Password cracking attempts in AzureAD", "Potential Password Spray Attack" based on periodic assessment of Azure Active Directory sign-in events and Okta console logins, "Attempts to sign in to disabled accounts", "Sign-ins from IPs that attempt sign-ins to disabled accounts", "High count of failed logins by a user", "Hi count of failed attempts same client IP", "SSH - Potential Brute Force", and "SecurityEvent - Multiple authentication failures followed by success".

This control may alert on repeated sign in attempts to the resource and successful logins from a suspicious location, IP address, or a user that does not commonly log in to the resource. Because this control is specific to Azure database offerings, the detection coverage is Minimal.

This control's "Authentication to Linux machines should require SSH keys" can obviate SSH Brute Force password attacks. Because this is specific to Linux, the coverage score is Minimal leading to an overall Minimal score.

This control can identify multiple connection attempts by external IPs, which may be indicative of Brute Force attempts, though not T1110.002, which is performed offline.

This control may alert on multiple successful and failed brute force attempts against SSH. There are no alerts for other methods of logging into Linux machines.

This control may detect successful and failed brute force attempts with logic that factors the IP, time between attempts, and other suspicious activity. The following alerts may be generated: "A logon from a malicious IP has been detected", "A logon from a malicious IP has been detected. [seen multiple times]", "Successful brute force attack", "Suspicious authentication activity".

This control may provide recommendations to implement multi-factor authentication, implement password security policies, and replacing password authentication with more secure authentication methods. This control can affect Azure, Azure cloud application, and endpoint credentials.

This control can be configured to completely block inbound access to selected ports until access is requested. This prevents any attempt at brute forcing a protocol, such as RDP or SSH, unless the attacker has the credentials and permissions to request such access. Even if permission has been granted to an authorized user to access the virtual machine, a list of authorized IP addresses for that access can be configured.

Advanced Protection Program enables the use of a security key for multi-factor authentication. This provides significant protection against Brute Force techniques attempting to gain access to accounts.

This control may mitigate brute force attacks by enforcing multi-factor authentication, enforcing strong password policies, and rotating credentials periodically. These recommendations are IAM best practices but must be explicitly implemented by a cloud administrator.

Multi-factor authentication (MFA) methods, such as SMS, can also be used to help protect user accounts from phishing attacks. MFA provides significant protection against password compromises, requiring the adversary to complete an additional authentication method before their access is permitted.

MFA can significantly reduce the impact of a password compromise, requiring the adversary to complete an additional authentication method before their access is permitted.

Due to the detection being limited to a specific set of application protocols, its coverage is Minimal resulting in a Minimal score.

The Amazon Inspector Best Practices assessment package can detect security control settings related to authentication and password policies on Linux endpoints. Specific security controls it can assess include "Disable password authentication over SSH", "Configure password maximum age", "Configure password minimum length", and "Configure password complexity" all of which impact the ability to brute force a password. This information can be used identify insecure configurations and harden the endpoints. Amazon Inspector does not directly protect against brute force attacks. Given Amazon Inspector can only assess these security controls on Linux platforms (although it also supports Windows), the coverage score is Minimal leading to an overall Minimal score.

The following AWS Config managed rules can identify configuration problems that should be fixed in order to ensure multi-factor authentication (MFA) is enabled properly, which can significantly impede brute force authentication attempts by requiring adversaries to provide a second form of authentication even if they succeed in brute forcing a password via one of these sub-techniques: "iam-user-mfa-enabled", "mfa-enabled-for-iam-console-access", "root-account-hardware-mfa-enabled", and "root-account-mfa-enabled". The "iam-password-policy" managed rule can identify insufficient password requirements that should be fixed in order to make brute force authentication more difficult by increasing the complexity of user passwords and decreasing the amount of time before they are rotated, giving adversaries less time to brute force passwords and making it more time consuming and resource intensive to do so. This is especially important in the case of Password Cracking, since adversaries in possession of password hashes may be able to recover usable credentials more quickly and do so without generating detectable noise via invalid login attempts. All of these controls are run periodically, but implemented policies are enforced continuously once set and coverage factor is significant, resulting in an overall score of Significant.

This control may mitigate brute force attacks by enforcing multi-factor authentication, enforcing strong password policies, and rotating credentials periodically. These recommendations are IAM best practices but must be explicitly implemented by a cloud administrator.

AWS Security Hub performs a check from the AWS Foundations CIS Benchmark that, if implemented, would help towards detecting the brute forcing of accounts. AWS Security Hub provides this detection with the following checks. 3.6 Ensure a log metric filter and alarm exist for AWS Management Console authentication failures This is scored as Minimal because it only applies to the AWS Management Console and not other access mechanisms (e.g., CLI, SDK, etc.). Furthermore, it does not detect brute-forcing methods for other components such as EC2 instances.

This control may protect against brute force techniques by enabling multi-factor authentication. All accounts that can be replace with single sign-on can benefit from a unified multi-factor authentication requirement.

Multiple conditions along can be combined to create fine-grained and specific policies that partially enforce access controls to account resources that adversaries may attempt to abuse: conditional access to Cloud APIs, blocking legacy authentication, requiring multi-factor authentication for users, block access by location, block access to unsupported devices, failed login attempts, account lockout policies, etc.. These features may require Microsoft Entra ID P2.

Conditional Access can be used to enforce MFA for users which can significantly reduce the impact of a password compromise, requiring an adversary to complete an additional authentication method before their access is permitted.

Conditional Access can be used to enforce MFA for users which can significantly reduce the impact of a password compromise, requiring an adversary to complete an additional authentication method before their access is permitted.

This control's "Suspected Brute Force attack (Kerberos, NTLM) (external ID 2023)" alert can detect these brute force sub-techniques. It incorporates a machine learning feature that should reduce the number of false positives. Similarly, its "Suspected Brute Force attack (LDAP) (external ID 2004)" alert can detect brute force attacks using LDAP simple binds. The "Suspected Brute Force attack (SMB) (external ID 2033)" alert is also relevant but the details are sparse.

Microsoft Defender security alerts explain the suspicious activities detected by Defender for Identity sensors on your network, and the actors and computers involved in each threat. Alert evidence lists contain direct links to the involved users and computers, to help make your investigations easy and direct. Defender security alerts are divided into the following categories or phases, like the phases seen in a typical cyber-attack kill chain. Learn more about each phase, the alerts designed to detect each attack, and how to use the alerts to help protect your network using the following links: Reconnaissance and discovery alerts Persistence and privilege escalation alerts Credential access alerts Lateral movement alerts Other alerts License: A Microsoft 365 security product license entitles customer use of Microsoft Defender XDR.

This control can detect some activity indicative of brute force attempts to login. Relevant alert is "Multiple failed login attempts".

Microsoft Secure Score is a measurement of an organization's security posture, with a higher number indicating more recommended actions taken. It can be found at Microsoft Secure Score in the Microsoft Defender portal. Following the Secure Score recommendations can protect your organization from threats. From a centralized dashboard in the Microsoft Defender portal, organizations can monitor and work on the security of their Microsoft 365 identities, apps, and devices. Your score is updated in real time to reflect the information presented in the visualizations and recommended action pages. Secure Score also syncs daily to receive system data about your achieved points for each action. To help you find the information you need more quickly, Microsoft recommended actions are organized into groups: Identity (Microsoft Entra accounts & roles) Device (Microsoft Defender for Endpoint, known as Microsoft Secure Score for Devices) Apps (email and cloud apps, including Office 365 and Microsoft Defender for Cloud Apps) Data (through Microsoft Information Protection)

Microsoft recommended the use of Passwordless authentication. This method provides the most secure MFA sign-in process by replacing the password with something you have, plus something you are or something you know.(e.g., Biometric, FIDO2 security keys, Microsoft’s Authenticator app). When combined with Conditional Access policies, Passwordless Authentication can significantly protect against the likelihood of adversary activity from credential attacks (e.g., brute force, token theft, etc.). License Requirements: All Microsoft Entra ID licenses

This control provides significant protection against password based attacks by completing obviating the need for passwords by replacing it with passwordless credentials.

Microsoft Entra ID Protection helps organizations detect, investigate, and remediate identity-based risks. These identity-based risks can be further fed into tools like Conditional Access to make access decisions or fed back to a security information and event management (SIEM) tool for further investigation and correlation. During each sign-in, Identity Protection runs all real-time sign-in detections generating a sign-in session risk level, indicating how likely the sign-in has been compromised. Based on this risk level, policies are then applied to protect the user and the organization. Risk-based Conditional Access policies can be enabled to require access controls such as providing a strong authentication method, perform multi-factor authentication, or perform a secure password reset based on the detected risk level. If the user successfully completes the access control, the risk is automatically remediated. License Requirements: Microsoft Entra ID P2

This control's "Require MFA for administrative roles" and "Ensure all users can complete multi-factor authentication for secure access" recommendations for enabling MFA can significantly lead to reducing the impact of a password compromise of accounts, requiring the adversary to complete an additional authentication method before their access is permitted. This control's "Do not expire passwords" recommendation also can lead to mitigating the Password Guessing or Cracking sub-techniques by disabling password reset which tends to lead to users selecting weaker passwords. This control's "Enable policy to block legacy authentication" and "Stop legacy protocols communication" recommendations can lead to protecting against these brute force attacks as Microsoft research has shown organizations that have disabled legacy authentication experience 67 percent fewer compromises than those where legacy authentication is enabled. Additionally, the same research shows that more than 99 percent of password spray and more than 97 percent of credential stuffing attacks use legacy authentication. This control's "Resolve unsecure account attributes" recommendation can lead to detecting accounts with disabled (Kerberos) Preauthentication which can enable offline Password Cracking. Because these are recommendations and do not actually enforce MFA, the assessed score is capped at Partial.

An incident in Microsoft Defender XDR is a collection of correlated alerts and associated data that make up the story of an attack. Microsoft 365 services and apps create alerts when they detect a suspicious or malicious event or activity. Individual alerts provide valuable clues about a completed or ongoing attack. Attacks typically employ various techniques against different types of entities, such as devices, users, and mailboxes. The result of this is multiple alerts for multiple entities in your tenant. Piecing the individual alerts together to gain insight into an attack can be challenging and time-consuming, Microsoft Defender XDR automatically aggregates the alerts and their associated information into an incident. A typical Incident Response workflow in Microsoft Defender XDR begins with a triage action, next is the investigate action, and finally is the response action. Microsoft 365 Defender Incident Response responds to Password Guessing attacks due to its password spray Incident Response playbook which monitors for many failed authentication attempts across various accounts that may result from password guessing attempts. License Requirements: Microsoft Defender XDR

Advanced hunting is a query-based threat hunting tool that lets you explore up to 30 days of raw data. Advanced hunting in Microsoft Defender XDR allows you to proactively hunt for threats across: Devices managed by Microsoft Defender for Endpoint, Emails processed by Microsoft 365, Cloud app activities, authentication events, and domain controller activities. With this level of visibility, you can quickly hunt for threats that traverse sections of your network, including sophisticated intrusions that arrive on email or the web, elevate local privileges, acquire privileged domain credentials, and move laterally to across your devices. Advanced hunting supports two modes, guided and advanced. Users use advanced mode if they are comfortable using Kusto Query Language (KQL) to create queries from scratch. Advanced hunting is a query-based threat hunting tool that lets you explore up to 30 days of raw data. Advanced hunting in Microsoft Defender XDR allows you to proactively hunt for threats across: Devices managed by Microsoft Defender for Endpoint, Emails processed by Microsoft 365, Cloud app activities, authentication events, and domain controller activities. With this level of visibility, you can quickly hunt for threats that traverse sections of your network, including sophisticated intrusions that arrive on email or the web, elevate local privileges, acquire privileged domain credentials, and move laterally to across your devices. Advanced hunting supports two modes, guided and advanced. Users use advanced mode if they are comfortable using Kusto Query Language (KQL) to create queries from scratch. Advanced Threat Hunting Detects Password Guessing attacks due to the IdentityLogonEvents table in the advanced hunting schema which contains information about all authentication activities related to Microsoft online services captured by Microsoft Defender for Cloud Apps which monitors authentication logs for system and application login failures of Valid Accounts. License Requirements: Microsoft Defender XDR, Microsoft Defender for Cloud Apps, Microsoft Defender for Office 365 plan 2

Defender for Identity LMPs are visual guides that help you quickly understand and identify exactly how attackers can move laterally inside your network. The purpose of lateral movements within the cyber-attack kill chain are for attackers to gain and compromise your sensitive accounts using non-sensitive accounts. Compromising your sensitive accounts gets them another step closer to their ultimate goal, domain dominance. To stop these attacks from being successful, Defender for Identity LMPs give you easy to interpret, direct visual guidance on your most vulnerable, sensitive accounts.

App governance in Defender for Cloud Apps is a set of security and policy management capabilities designed for OAuth-enabled apps registered on Microsoft Entra ID, Google, and Salesforce. App governance delivers visibility, remediation, and governance into how these apps and their users access, use, and share sensitive data in Microsoft 365 and other cloud platforms through actionable insights and automated policy alerts and actions. App governance also enables you to see which user-installed OAuth applications have access to data on Microsoft 365, Google Workspace, and Salesforce. It tells you what permissions the apps have and which users have granted access to their accounts. App governance insights enable you to make informed decisions around blocking or restricting apps that present significant risk to your organization App Governance Detects Password Guessing attacks due to App Governance monitoring aggregated sign-in activity for each app and tracking all risky sign-in's. License Requirements: Microsoft Defender for Cloud Apps

MFA can significantly reduce the impact of a password compromise, requiring the adversary to complete an additional authentication method before their access is permitted.

MFA can significantly reduce the impact of a password compromise, requiring the adversary to complete an additional authentication method before access is permitted.

The password restrictions provided by the default Password policy along with the lockout threshold and duration settings is an effective protection against this Password Guessing sub-technique.

A password policy is applied to all user accounts that are created and managed directly in Microsoft Entra ID. By default, an account is locked out after 10 unsuccessful sign-in attempts with the wrong password. Further incorrect sign-in attempts lock out the user in real time for increasing durations of time. License Requirements: Microsoft Entra ID Free, Microsoft Entra ID P1, or Microsoft Entra ID P2

Microsoft Entra Password Protection efficiently blocks known weak passwords likely to be used in password guessing attacks. License Requirements: Microsoft Entra ID Free, Microsoft Entra ID P1, or Microsoft Entra ID P2