
APT29 compromised popular sites by injecting obfuscated JavaScript that quietly redirected around 10% of visitors to actor‑controlled domains. These pages mimicked Cloudflare’s auth flow exactly, leading users to generate and enter Microsoft device authentication codes effectively allowing attackers to enroll their own devices.
Who’s Affected & What’s at Risk
Any user visiting a compromised website could be tricked into authorizing a malicious device — even if they thought they were completing a genuine security flow. The persistent authorization could give APT29 long‑term access to corporate environments. No AWS systems were harmed but the campaign leveraged trust in browser-to‑device flows.
Why This Matters
- Multi-level deception: Users see credible-looking flows (Cloudflare + device code), yet the authentication itself is exploited.
- Obfuscated attacks: Randomized client-side triggers reduce detection, and cookie flags prevent repeat alerts.
- Persistent access risk: Device code auth can bypass typical MFA/logging, enabling stealthy lateral movement.
- Supply chain exposure: Even unassuming websites can become APT supply vectors.
- Effective disruption: Amazon’s swift intervention highlights how cross-org coordination is vital to halt advanced campaigns.
Do-Now Checklist)
- Continuously audit website content for unauthorized JavaScript injections especially on high-traffic or third-party sites.
- Treat device-code auth as high-risk flows monitor and restrict issuance via policy (e.g., conditional access, network constraints).
- Track device enrollment events from unusual domains or IPs; flag anomalies.
- Deploy endpoint/web filters that inspect obfuscated scripts or domains masquerading as Cloudflare or other trusted brands.
- Collaborate early with cloud/identity providers when detecting phishing-like redirects or auth flows.
- Conduct simulated watering-hole attacks to test perimeter and user-flow resilience.
- Create playbooks for rapid coordinated response (threat intel, DNS sinkhole, domain takedown, site isolation).
Finstein’s Take: When Trust Gets Weaponized, Controls Must Evolve
APT29 didn’t hack the cloud this time they hacked trust. By turning Microsoft’s device code flow and compromised websites into attack surfaces, they proved that even the most familiar security experiences can be weaponized.
At Finstein Cyber, we believe that waiting for vendors to patch isn’t enough. Proactive defense means testing the edges of trust before adversaries do.
If your identity flows aren’t tested and hardened, attackers will make them their playground.
Want to test your exposure before the next wave hits?
praveen@finstein.ai | cyber.finstein.ai
source: https://cybersecuritynews.com/amazon-dismantles-russian-apt-29-infrastructure/
https://aws.amazon.com/blogs/security/amazon-disrupts-watering-hole-campaign-by-russias-apt29
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