Azure CLI Password Spray Attack: A Step-by-Step Compliance Response Guide

Introduction

Between June 12 and June 26, 2024, a massive password spray campaign targeted Microsoft Azure CLI, launching over 81 million login attempts and compromising at least 78 user accounts across 64 organizations. The attack originated from AS32167 (LSHIY LLC), a Hong Kong/China-based hosting provider, and exploited the OAuth ROPC flow, which bypasses MFA if not properly configured. Huntress reported a 155x increase in credential spray attacks over six months, underscoring the growing threat landscape.

This guide is for compliance and security teams who need to respond effectively to such an attack. You will learn immediate incident response steps, regulatory notification obligations under NIS2 (EU), DORA (EU), and SEC cyber disclosure rules (US), and long-term hardening measures. A compliance reporting checklist is included to help you meet your obligations.

This content is for informational purposes only and does not constitute legal advice.

Prerequisites

Before beginning the response process, ensure you have:

• Access to your Azure AD/Microsoft 365 security portal (including Azure AD logs, sign-in logs, audit logs)
• Incident response playbook (or create one based on NIST CSF/ISO 27001 guidance)
• List of regulatory contacts (e.g., national competent authority for NIS2, financial regulator for DORA, SEC for US public companies)
• Communication templates for internal and external stakeholders
• Tools for log analysis and monitoring (e.g., Microsoft Sentinel, third-party SIEM)

Step 1: Immediate Incident Response

1.1 Confirm the Attack

Review Azure AD sign-in logs for the following indicators:

• High volume of failed authentication attempts from IPv6 addresses associated with AS32167
• Successful sign-ins from unusual locations or IPs
• Use of the ROPC flow (OAuth 2.0 Resource Owner Password Credentials grant) in authentication

Use Azure AD workbooks or Microsoft Sentinel to query for password spray patterns. For example, look for sign-ins with multiple failed attempts followed by a success from the same IP within a short period.

1.2 Contain Compromised Accounts

Immediately disable or reset credentials for any accounts identified as compromised. Follow the principle of least privilege: if the account had administrative roles, revoke those roles and re-evaluate need. Force password reset for all potentially affected users.

1.3 Block Malicious IPs

Create a Conditional Access policy to block sign-ins from the known malicious IP ranges. For AS32167, block the IPv6 range(s) used in the attack. Also consider blocking legacy authentication protocols, especially ROPC, which is deprecated in OAuth 2.1.

1.4 Enable and Enforce MFA

If not already enforced, enable MFA for all users, including service accounts where possible. Ensure MFA covers all authentication flows, including ROPC. Microsoft recommends using Conditional Access to require MFA for all cloud apps. Review your MFA configuration to avoid gaps like group-based or location-based exclusions.

Step 2: Regulatory Notification Obligations

Depending on your organization's jurisdiction and sector, you may have legal obligations to report this incident to regulators. Below are the key frameworks and their requirements.

2.1 NIS2 Directive (EU)

NIS2 (Directive (EU) 2022/2555) applies to essential and important entities across 18 sectors. It requires:

• Early warning: Within 24 hours of becoming aware of a significant incident, submit an early warning to the competent authority or CSIRT.
• Notification: Within 72 hours, provide a detailed notification with initial assessment, severity, and impact.
• Final report: Within one month, submit a final report with root cause analysis and lessons learned.

For a password spray attack that compromises accounts, this qualifies as a significant incident if it affects service availability or data confidentiality. Check your national transposition (deadline was 17 October 2024) for specific thresholds.

2.2 DORA (EU Financial Entities)

DORA (Regulation (EU) 2022/2554) applies from 17 January 2025 to financial entities including banks, insurers, and investment firms. Requirements include:

• Initial notification: Within 4 hours of classifying the incident as major, notify the competent authority.
• Intermediate report: Within 72 hours, provide an update.
• Final report: Within one month, submit a comprehensive report.

DORA also requires reporting of significant cyber threats (not just incidents). A password spray campaign targeting your infrastructure may qualify.

2.3 SEC Cybersecurity Disclosure Rules (US Public Companies)

The SEC's final rule (July 2023) requires public companies to disclose material cybersecurity incidents on Form 8-K within 4 business days. For this attack, determine materiality based on:

• Number of accounts compromised and their access levels
• Data exfiltration risk (even if not confirmed)
• Impact on business operations or financial condition
• Reputational harm

If material, file Form 8-K within 4 business days. Also update Form 10-K annually with risk management and governance details.

2.4 Other US Obligations

Depending on your industry, you may also need to report under:

• GLBA Safeguards Rule: Financial institutions must report incidents to primary federal regulator.
• State breach notification laws: If personal data is affected, notify affected individuals and state attorneys general (typically within 30-60 days).
• CIRCIA (critical infrastructure): Once final rule is in effect, report significant incidents to CISA within 72 hours.

Step 3: Long-Term Hardening Measures

3.1 Enforce MFA for All Authentication Flows

Ensure MFA is required for all applications and authentication protocols, especially ROPC. Microsoft recommends disabling ROPC entirely and using modern authentication flows like OAuth 2.0 authorization code with PKCE. Use Conditional Access policies to enforce MFA for all cloud apps.

3.2 Implement Conditional Access Policies

Create policies to:

• Block sign-ins from untrusted IP ranges (e.g., known malicious ASNs)
• Require MFA for risky sign-ins (based on risk level)
• Require compliant devices (e.g., Intune-managed)
• Limit access based on location (e.g., block countries where you have no business)

3.3 Monitor for Password Spray and Brute Force

Set up monitoring using Azure AD Identity Protection, Microsoft Sentinel, or third-party SIEM. Create alerts for:

• Multiple failed sign-ins from a single IP across multiple accounts
• Sign-ins using legacy authentication protocols
• Unusual geographic patterns

For geopolitical threat intelligence, consider platforms like AIGovHub SENTINEL, which monitors 435+ intelligence sources and can provide early warnings of emerging attack campaigns.

3.4 Review and Update Identity Governance

Conduct a review of all user accounts, especially privileged roles. Implement just-in-time (JIT) access for administrative roles using Privileged Identity Management (PIM). Remove unused accounts and enforce strong password policies (e.g., ban common passwords, enforce length over complexity).

3.5 Conduct Regular Security Awareness Training

Train employees to recognize phishing and social engineering attacks that often accompany password spray campaigns. Emphasize the importance of using MFA and reporting suspicious activity.

Step 4: Compliance Reporting Checklist

Use this checklist to ensure you meet your regulatory obligations:

• [ ] Confirm incident qualifies as significant/material under applicable frameworks
• [ ] Submit early warning (NIS2: 24h) or initial notification (DORA: 4h) if required
• [ ] File Form 8-K with SEC within 4 business days if material (US public companies)
• [ ] Notify affected individuals and state AGs under state breach notification laws (if personal data involved)
• [ ] Report to GLBA regulator if financial institution
• [ ] Submit detailed notification (NIS2: 72h; DORA: 72h intermediate report)
• [ ] Conduct root cause analysis and document lessons learned
• [ ] Submit final report (NIS2/DORA: within one month)
• [ ] Update incident response playbook based on findings
• [ ] Review and update cybersecurity risk management program

For continuous compliance monitoring and controls management, tools like AIGovHub CCM can automate evidence collection and remediation workflows, helping you demonstrate compliance to regulators.

Common Pitfalls

• Underestimating the scope: Password spray attacks often go undetected because individual attempts are spread across many accounts. Review logs thoroughly.
• Ignoring legacy protocols: ROPC and other legacy auth flows bypass MFA. Disable them unless absolutely necessary.
• Delaying notification: Regulatory deadlines are strict. Start the notification process immediately, even if you don't have all details.
• Failing to document: Regulators expect a clear timeline and evidence of actions taken. Maintain an immutable audit log.
• Not updating MFA policies: Ensure MFA covers all apps and all users. Avoid group-based or location-based exclusions.

FAQ

What is a password spray attack?

A password spray attack is a type of brute-force attack where an attacker attempts a few commonly used passwords against many user accounts to avoid account lockout thresholds. In the Azure CLI campaign, attackers used over 81 million attempts across many accounts, eventually compromising 78 accounts.

Why did the Azure CLI password spray bypass MFA?

The attack exploited the OAuth ROPC (Resource Owner Password Credentials) flow, which does not support MFA natively. If MFA is not configured to cover this flow (e.g., via Conditional Access), the attacker can authenticate using just username and password.

Do I need to report this incident if no data was stolen?

Yes, many regulations require reporting based on the incident's impact on availability, confidentiality, or integrity, even if no data exfiltration is confirmed. For example, NIS2 and DORA consider incidents that disrupt services or indicate a significant cyber threat as reportable.

How can I detect password spray attacks in my environment?

Monitor Azure AD sign-in logs for patterns such as multiple failed logins from the same IP across different accounts, especially from unusual locations. Use Azure AD Identity Protection or third-party SIEM tools to automate detection.

What is the best way to prevent password spray attacks?

Enforce MFA for all users and all authentication flows, disable legacy authentication protocols like ROPC, implement Conditional Access policies to block suspicious sign-ins, and use strong password policies (e.g., ban common passwords, enforce length).

Next Steps

Now that you have a response plan, take these actions:

1. Review your current MFA configuration and ensure it covers all authentication flows.
2. Disable ROPC if not needed, or enforce MFA via Conditional Access for that flow.
3. Set up monitoring for password spray patterns using Microsoft Sentinel or a SIEM.
4. Update your incident response playbook with specific steps for credential-based attacks.
5. Evaluate continuous compliance monitoring tools like AIGovHub CCM to automate evidence collection and remediation workflow.
6. For geopolitical threat intelligence, consider AIGovHub SENTINEL to receive real-time alerts on emerging attack campaigns.