Changed relationship details
A familiar supplier introduces a new bank account, contact, portal, file-sharing method, or reply address.
Vendor Email Compromise Awareness
How to Recognize and Report Vendor Email Compromise
Vendor email compromise uses a supplier's real or convincingly impersonated account to target customers, partners, or employees through an existing business relationship.
Use this guide to turn the threat into a clear employee decision, a safe practice scenario, and a reporting step your organization can support.
Plain-English definition • Warning signs • Safe simulation ideas • Reporting practice
01Understand the threat
Vendor Email Compromise: a practical definition
Vendor email compromise uses a supplier's real or convincingly impersonated account to target customers, partners, or employees through an existing business relationship.
The sender may pass ordinary familiarity checks because the mailbox or conversation is genuine. The organization needs process controls for changed payment details, documents, and unusual requests even when the email address is known.
Source: CISA Phishing Guidance
02Recognition clues
Warning signs employees can check in a vendor email compromise message
No single clue proves that a message is malicious. Teach employees to combine the request, sender, business context, destination, and available verification route before acting.
Conversation shift
A normal thread changes topic, tone, destination, urgency, or requested action without expected business context.
Control avoidance
The sender asks the employee to skip the account owner, purchase order, callback, approval, or supplier-change process.
03Safe response
Move from suspicion to a supported next step
| Moment | Employee action | Program preparation |
|---|---|---|
| Before acting | Use the supplier contact and account-change process already on file, and involve the internal relationship owner before accepting a consequential change. | Publish the authentic contact, application, or reporting route somewhere employees can reach without using the message. |
| When uncertain | Pause the request and report it through the approved channel with enough context for review. | Explain what the response team needs and how employees will know that their report was received. |
| After an interaction | Stop, contact the responsible team promptly, and describe the action taken without hiding the mistake. | Provide a well-known response route and avoid communications that discourage early reporting. |
Source: NIST: Recognizing, verifying, and reporting phishing
04Practice safely
Vendor Email Compromise simulation and discussion ideas
Choose one learning objective per exercise. Use fictional people, organizations, accounts, payments, documents, and events, and test the reporting route before sending to employees.
Supplier bank change
Use an invented vendor and account to practice independent confirmation and approval.
Compromised-thread tabletop
Discuss how a genuine-looking fictional conversation can change into a payment or credential request.
New document portal
Practice contacting the known supplier owner when a familiar sender introduces an unexpected file service.
05Campaign workflow
Build the exercise around a decision employees can repeat
- 1
Define the behavior
Write down the vendor email compromise clue being practiced, the expected action, the authorized audience, and the owner of follow-up.
- 2
Confirm the real process
Test the independent verification route, message-reporting option, response handoff, and employee support path from a representative account.
- 3
Pilot the scenario
Check delivery, links, landing content, accessibility, event records, automated inspection, stop conditions, and the explanation employees will receive.
- 4
Review in context
Reconcile intended recipients, successful deliveries, unique employee events, verified reports, response handling, and completed follow-up before drawing conclusions.
Source: NIST SP 800-50 Rev. 1: Building a Cybersecurity and Privacy Learning Program
06Useful measurement
Evaluate recognition, reporting, and the surrounding process
Record actual counts and denominators for delivery, unique recipient events, reports, and follow-up. Separate automated email inspection and repeat events where the available evidence supports doing so.
A vendor email compromise exercise samples one scenario under one set of conditions. It does not establish an employee's intent, overall security awareness, or likelihood of responding the same way to a real attack.
Use findings to improve the real workflow: clearer verification instructions, easier reporting, faster response handling, better role-specific training, or a business control that reduces reliance on email alone.
Common questions
Common questions about Phishmake's features, onboarding, and support, answered to help you get started with confidence.
Can a message from a real vendor address still be malicious?
Yes. A mailbox or connected workflow may be compromised. Important changes should follow the established supplier-verification and approval process.
Who owns vendor-request verification?
Define the owner before an incident. Procurement, finance, the business relationship owner, security, and support may each have a role; employees need one clear route for starting the check.
Can vendor email compromise be used in a phishing simulation?
It can be practiced when the scenario is authorized, proportionate, and tied to a real reporting or verification process. Use fictional vendors, contacts, accounts, invoices, and conversations. Do not imitate an active supplier incident, contact external parties, or place simulation data in production purchasing systems.
How should vendor email compromise simulation results be measured?
Review successful delivery, unique employee events, reports, response handling, and completed follow-up. Include scenario difficulty and operating context, and do not treat a click or report as a complete measure of employee risk.
Sources & further reading
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