Token Bingo: Don’t Let Your Code be the Winner

Key Takeaways

• A large-scale phishing campaign is utilizing the Kali365 Live Phishing-as-a-Service (PhaaS) platform to abuse the OAuth 2.0 Device Authorization Grant flow.
• Threat actors trick victims into authorizing device codes, granting them OAuth access and refresh tokens without ever handling the victim's passwords.
• Kali365 Live supports both device code abuse and Adversary-in-the-Middle (AiTM) session capture via Cloudflare Workers.
• Post-compromise, attackers establish persistence by creating malicious inbox rules to suppress security alerts and by registering new devices in the victim's environment.
• The Kali365 Live desktop client uses a distinct, high-confidence User-Agent string: 'kali365-live/1.0.0'.

Affected Systems

• Microsoft 365
• Microsoft Entra ID
• OAuth 2.0 Device Authorization Grant flow

Attack Chain

The threat actor delivers a phishing email containing a malicious attachment or link that redirects the victim to a Cloudflare Worker-hosted landing page. This page dynamically generates a legitimate Microsoft OAuth device code and instructs the victim to enter it at microsoft.com/devicelogin. Once the victim authenticates and completes MFA, the Kali365 backend captures the resulting OAuth access and refresh tokens. The attacker then uses these tokens to access the victim's mailbox, establish persistence by registering new devices, and create malicious inbox rules to suppress security notifications.

Detection Availability

• YARA Rules: No
• Sigma Rules: No
• Snort/Suricata Rules: No
• KQL Queries: No
• Splunk SPL Queries: No
• EQL Queries: No
• Other Detection Logic: No

The article does not provide specific detection rules or queries, but outlines behavioral indicators and Conditional Access policy recommendations.

Detection Engineering Assessment

EDR Visibility: Low — This is an identity-based attack occurring entirely within cloud environments (Microsoft 365/Entra ID) and the victim's web browser, leaving minimal footprint on the endpoint OS. Network Visibility: Medium — Network logs may capture connections to the Cloudflare Worker domains or the specific User-Agent strings, but the actual authentication traffic to Microsoft is encrypted and legitimate. Detection Difficulty: Hard — The attack abuses legitimate OAuth flows, making malicious device code authorizations difficult to distinguish from legitimate ones without strict Conditional Access policies or behavioral baseline deviations.

Required Log Sources

• Azure AD Sign-in Logs
• Azure AD Audit Logs
• Microsoft 365 Unified Audit Log
• Network Proxy/Web Gateway Logs

Hunting Hypotheses

Control Gaps

• Standard MFA
• Credential-based Phishing Defenses
• Endpoint Detection and Response (EDR)

Key Behavioral Indicators

• User-Agent: kali365-live/1.0.0
• Inbox rules suppressing security keywords
• Device Code Flow sign-ins from non-standard devices/locations

False Positive Assessment

• Medium, as legitimate use of the device code flow by IoT devices, smart TVs, or CLI tools can trigger detections if not properly filtered by Conditional Access policies or baseline tuning.

Recommendations

Immediate Mitigation

• Block Device Code Flow using Conditional Access (CA) policies where not explicitly required.
• Search for and remove suspicious inbox rules designed to suppress security notifications.
• Revoke active sessions and refresh tokens for any accounts suspected of being compromised.

Infrastructure Hardening

• If device code flow is required, restrict it via CA policies to specific trusted IPs, device platforms (e.g., Android for meeting rooms), or specific service account user groups.
• Enable sign-in risk policies via Microsoft Entra ID Protection to detect anomalous sign-ins.

User Protection

• Implement phishing-resistant MFA (e.g., FIDO2 keys) where possible to mitigate the risk of AiTM and token theft.

Security Awareness

• Train users to recognize device code phishing lures and understand that entering a code grants access to their account.
• Educate employees on the legitimate use cases for device codes (e.g., smart TVs) versus unexpected prompts on laptops or phones.

MITRE ATT&CK Mapping

• T1566.001 - Phishing: Spearphishing Attachment
• T1566.002 - Phishing: Spearphishing Link
• T1528 - Steal Application Access Token
• T1556 - Modify Authentication Process
• T1098 - Account Manipulation
• T1564.008 - Hide Artifacts: Email Hidden Rules
• T1114.002 - Email Collection: Remote Email Collection

Additional IOCs

• Ips:
  • 199[.]91[.]220[.]111 - Cloud Hosting sibling instance for the phishing infrastructure.
• Domains:
  • kali365[.]xyz - Kali365 Live panel domain.
  • api[.]kali365[.]xyz - Kali365 Live panel API domain.
  • fn4z-b84o-xn9y[.]tesouraria-ts-tranmissions-com-s-account[.]workers[.]dev - Cloudflare Worker domain hosting the phishing landing page (extracted from image).
• Urls:
  • hxxps://v2[.]duemineral[.]uk - Panel URL used by the Kali365 Live desktop application (extracted from image).
• File Hashes:
  • 09bb7e568e573497e22bfa3f36d71fe9d104899826608affedb25d988f391c85 (SHA256) - Reference HTML Phishing Page.
  • 2fa6fc2199d3be55e240500d87e4484f39b9315bf336be25434f6716b8d28ec8 (SHA256) - Reference HTML Phishing Page.
• Other:
  • python-requests/2.31.0 - User-Agent observed for backend egress in the campaign context.