RaccoonO365 Phishing Network Dismantled — CyberDudeBivash Authority Report

-

 


Executive Summary

Threat Profile & Attack Mechanics

What RaccoonO365 Did

  • It offered phishing kits that impersonated trusted brands (Microsoft, Adobe, SharePoint, etc.), making very convincing fake login pages. The Hacker News+1

  • They used Telegram to distribute the service, provide support, advertise features. The infrastructure included Cloudflare Worker scripts and domain fronting / worker accounts to evade detection. IT Pro+2CyberScoop+2

  • Some phishing campaigns included tax-themed messages, targeting thousands of orgs in the U.S., including healthcare entities. The Official Microsoft Blog+2The Hacker News+2

Why It Worked

  • Low technical barrier: even less-skilled threat actors could use the service.

  • Kit subscription model meant continual updates and support.

  • Use of legitimate infrastructure (Cloudflare) gave them performance + partial legitimacy masking.

  • Automation: claims of ability to bypass MFA + scale to thousands of targets daily. The Official Microsoft Blog+2The Hacker News+2

Impact & Risk

  • Credentials stolen can allow access to corporate email, cloud storage, internal systems.

  • Attackers may bypass MFA using session hijacking or link replays if credential + cookie are both harvested.

  • Health care organizations are especially vulnerable due to sensitivity of data and regulatory exposure.

  • Subscription phishing services scale risk: many small businesses get impacted via mass phishing.

Detection & Threat Hunting

Indicators of Compromise

  • Phishing emails spoofing Microsoft/Office 365, often with Microsoft branding. Look for lookalike domains. IT Pro+1

  • Domains registered for phishing (lookalikes), often using recent registration dates.

  • Cloudflare Worker accounts/scripts associated with those domains.

  • Interstitial or warning pages outside known trusted sites.

  • Multiple login attempts or credential harvests logged at Microsoft or via email security tools.

SOC / SIEM Hunt Queries

A) Domain registration + phishing domain detection

index=dns_logs | where domain_registration_date > now()-30d
| search domain matches "*microsoft-login*" OR "*office365-portal*" OR similar lookalike patterns
| table domain, registration_date, registrar

B) Cloudflare Worker usage monitoring

  • Monitor HTTP requests routed through Cloudflare Workers; flag those with rarely used worker accounts or high traffic + suspicious patterns.

C) Email gateway logs / phishing increase

  • Email subject lines referencing tax, billing, invoice + request login link.

  • Multiple recipients per email (mass phishing).

Mitigations & Defensive Measures

Immediate Steps

  • Enforce MFA / two-factor strictly for Microsoft 365 / Office accounts, with phishing-resistance where possible.

  • Block phishing domains via DNS filtering / email gateway.

  • Enable safe links / attack surface reduction on email clients.

Short-term (Weeks)

  • Deploy Anti-Phishing campaigns / training.

  • Set up alerts for Credential appearances on dark web / leaked lists.

  • Monitor Cloud infrastructure for rogue worker scripts / domain fronting.

Long-term & Strategic Controls

  • Use Zero Trust Identity: Conditional Access based on device, location, reputation.

  • Integrate cloud email / identity threat intelligence feeds.

  • Automate takedown support / domain monitoring via policy / law enforcement integration.

Business & Compliance Implications

  • Regulatory risk (GDPR, HIPAA) for healthcare or personal data exposures resulting from account compromise.

  • Reputational damage, especially for organizations in sectors with sensitive or critical services.

  • Insurance: policies may require evidence of phishing awareness training, identity controls to pay out.

Recommendations & Roadmap

  1. Inventory all Microsoft 365 accounts; ensure no reused credentials across services.

  2. Review email security posture: ensure link / domain filtering, sandboxing.

  3. Harden identity: implement phishing-resistant MFA + Conditional Access.

  4. Procure or subscribe to threat intelligence feeds for phishing kit hosting / domain abuse.

  5. Prepare playbooks for credential breach, email compromise, phishing incidents.


#CyberDudeBivash #RaccoonO365 #PhishingAsAService #PhaaS #Cloudflare #Microsoft #CredentialTheft #IdentitySecurity #ThreatIntel #ZeroTrust

CTAs:

  • “Check your Microsoft account’s activity logs — reset passwords if unknown login.”

  • “Audit domains / emails impersonating your brand.”

  • “Train staff: phishing attacks still evolve.”

Comments

Post a Comment

Popular posts from this blog

CyberDudeBivash Rapid Advisory — WordPress Plugin: Social-Login Authentication Bypass (Threat Summary & Emergency Playbook)

-
Image
  TL;DR: A class of vulnerabilities in WordPress social-login / OAuth plugins can let attackers bypass normal authentication flows and obtain an administrative session (or create admin users) by manipulating OAuth callback parameters, reusing stale tokens, or exploiting improper validation of the identity assertions returned by providers. If you run a site that accepts social logins (Google, Facebook, Apple, GitHub, etc.), treat this as high priority : audit, patch, or temporarily disable social login until you confirm your plugin is safe. This advisory gives you immediate actions, detection steps, mitigation, and recovery guidance. Why this matters (short) Social-login plugins often accept externally-issued assertions (OAuth ID tokens, authorization codes, user info). If the plugin fails to validate provider signatures, nonce/state values, redirect URIs, or maps identities to local accounts incorrectly , attackers can craft requests that the site accepts as authenticated. ...
Read more

Hackers Injecting Malicious Code into GitHub Actions to Steal PyPI Tokens CyberDudeBivash — Threat Brief & Defensive Playbook

-
Image
  SUMMARY  Attackers are modifying GitHub Actions workflows (via compromised accounts, malicious PRs, or forged commits) to add steps that exfiltrate PyPI (or other package registry) publishing tokens. With those tokens they publish backdoored packages or download private packages — a supply-chain multiplier. Defend by eliminating long-lived secrets, switching to OIDC/ephemeral credentials, hardening workflow controls, monitoring workflow changes and secret usage, and rotating tokens immediately if you suspect compromise. How attackers typically operate  Gain write access to repo or CI/CD config (via compromised developer account, stolen token, privilege abuse, or merge of malicious PR). Modify or add a workflow file that runs in the repo’s runner context (self-hosted or GitHub-hosted). Add steps that read repository secrets (e.g., PYPI_TOKEN ) or create credentials files ( ~/.pypirc ), then send the token to attacker-controlled endpoints or push a malicious p...
Read more

Exchange Hybrid Warning: CVE-2025-53786 can cascade into domain compromise (on-prem ↔ M365) By CyberDudeBivash — Cybersecurity & AI

-
Image
  Executive summary CVE-2025-53786 is a post-authentication elevation of privilege in Microsoft Exchange hybrid deployments . If an attacker first gains admin on an on-prem Exchange server , they can abuse the legacy “shared service principal” trust used by Hybrid Configuration to escalate into Exchange Online —potentially leading to full cloud+on-prem domain compromise . CISA issued Emergency Directive ED-25-02 with a deadline of 9:00 a.m. EDT on August 11, 2025 for U.S. federal agencies; Microsoft urges all hybrid customers to take the same steps: apply the April 2025 Hotfix Updates , migrate to the dedicated Exchange Hybrid app , and reset/clean up service principal credentials . cisa.gov +1 TECHCOMMUNITY.MICROSOFT.COM +1 Why this is dangerous: actions initiated from the on-prem Exchange side may not show up as obviously malicious in M365 audit trails, making cloud abuse harder to spot if you’ve not modernized the trust. TechRadar What is actually vulnerable? (trust...
Read more