Your Helpdesk Is the New Front Door: BPO Supply Chain Attacks Bypass MFA at Scale
Two Campaigns, One Broken Trust Model
Two distinct threat actors are exploiting the same architectural flaw: outsourced support vendors sit inside your identity perimeter with the ability to reset passwords, re-enroll MFA, and modify authentication workflows — and attackers are going through them instead of through you.
UNC6783 ('Mr. Raccoon') targets BPO providers handling customer support for large enterprises. Google's threat intelligence documents the playbook: compromise the BPO, then use their legitimate access to steal Zendesk tickets en masse. The Adobe breach alone yielded 13 million support tickets stolen through a compromised Indian BPO. Their phishing kit uses spoofed Okta pages following patterns like company.zendesk-support##.com and captures clipboard contents to bypass TOTP codes copied from authenticator apps. Only FIDO2/hardware keys resist this technique.
Storm-2755 ('Payroll Pirate') takes a different path to the same destination. Microsoft tracks this actor using SEO poisoning and malvertising to drive employees to fake Office 365 login pages. An adversary-in-the-middle proxy captures session tokens, defeating MFA entirely. Once inside, they search for HR and payroll contacts, create inbox rules to hide their activity, then email HR to redirect direct deposit information. Vulnerable U — a security-focused organization — was itself targeted by this campaign.
Why Your EDR Won't Save You
These attacks are invisible to endpoint detection because nothing anomalous happens on the endpoint. The compromise occurs in the identity layer — legitimate credentials, legitimate SSO flows, legitimate-looking user behavior. Your EDR fires when malware executes; it doesn't fire when a valid session token authenticates through Okta.
| Detection Layer | Effectiveness | Gap |
|---|---|---|
| EDR/Endpoint | Low | Valid credentials + legitimate SSO = no anomaly |
| Network/DNS | Medium | Can detect spoofed Okta domains if DNS telemetry monitored |
| Identity Analytics | High | Impossible travel, MFA re-enrollment spikes detectable |
| BPO Access Monitoring | High | Most orgs don't monitor support vendor identity ops at all |
| FIDO2 MFA | Preventive | Keys can't be replayed through spoofed pages |
If your BPO agent can reset an executive's password without a second verification channel, that's your highest-priority finding today.
The Payroll Endgame
Storm-2755's targeting of payroll is particularly insidious because the fraud often isn't detected until an employee reports a missing paycheck — days or weeks after the redirect. Zephyr Energy lost €700K to a contractor payment redirect using similar TTPs. The actor creates inbox rules to auto-delete confirmation emails, ensuring neither the compromised employee nor HR sees evidence of the change until it's too late.
What to do
Map every BPO, call center, and helpdesk contractor that can trigger password resets, MFA re-enrollment, or Okta session modifications — then apply conditional access policies restricting these actions to verified contexts
Deploy FIDO2/WebAuthn hardware keys to all admin accounts, helpdesk staff, HR/payroll teams, and executives within 30 days
Mandate out-of-band phone verification for all payroll/direct deposit changes — no exceptions for email or chat requests
Monitor for spoofed domains matching patterns like company.zendesk-support##.com and deploy impossible travel detection on Okta