Organizations are investing heavily in technical safeguards, user training, and layered security strategies. That’s a good thing. But as your defenses improve, attackers are adapting.
In 2025, the leading tactic we’re seeing isn’t about breaking into your systems directly. It’s about compromising your vendors’ accounts and using them as trusted entry points into your organization.
Your Security May Be Strong, But What About Theirs?
Today’s threat actors often go after vendors, subcontractors, and partners with weaker security. Once they gain access—usually through business email compromise—they hijack real conversations and impersonate people your team already knows and trusts.
Example: A construction firm received a follow-up email from a familiar subcontractor. It referenced a real project and included a link to “updated plans.” The message used the same tone, language, and signature. But the link led to a spoofed login page. When the project manager entered their credentials, the attackers gained access to internal RFPs and communications within hours.
These emails aren’t broad phishing blasts. They’re carefully timed, tailored, and often reference actual meetings or documents. The attackers are patient, observant, and increasingly sophisticated.
How It Works: The Modern Threat Actor Playbook
- Compromise a 3rd-Party Account: The attacker gains access to the email account of a vendor your team regularly works with—like an IT support rep, contractor, or outsourced finance partner.
- Observe and Blend In: Instead of attacking right away, they observe. They read past email threads and analyze patterns. They might even learn your internal project codenames or proposal due dates.
Example: A healthcare organization received an email from its managed print services vendor referencing an upcoming lease renewal. The email matched prior conversation history and asked the team to review a revised PDF. The file contained no malware—it simply led to a credential phishing portal.
- Launch The Trigger Message: After weeks of watching and waiting, the attacker finally acts:
“Hey Rachel—just following up on last Thursday’s call. Attaching the invoice for the maintenance contract. Let me know if you need anything else before end of day.”
Because it looks like a normal continuation of a real conversation, defenses are lowered. Your team clicks.
- Capture Credentials
A user logs in to view the file. The site looks like Microsoft, Google Drive, or DocuSign. But it isn’t. The credentials go straight to the attacker. - Move Inside Your Environment
Now the attacker is in your system, sending emails, escalating privileges, scheduling fake vendor payments, or launching ransomware—all while hiding in plain sight.
Why This Bypasses Traditional Defenses
There’s no virus. No obviously malicious file. From your security tools’ perspective, it’s just a normal user logging in with valid credentials.
When trust is exploited, traditional perimeter defenses like firewalls and antivirus aren’t enough.
What You Can Do Today
- Reevaluate Vendor Risk
Start with a vendor risk assessment, especially for anyone with system access or regular communication. Ask about MFA usage, security awareness, and breach history.
Pro Tip: Include vendors like legal, accounting, or marketing—areas with high email volume and often weaker security.
- Use Identity-Based Security Tools
Deploy conditional access rules, monitor for impossible travel logins, and enable MFA everywhere. Even better, implement tools like Microsoft Defender for Identity or Okta Behavior Detection that monitor for anomalies even after login. - Train for Tactics, Not Just Tools
Go beyond generic phishing training. Show examples of real conversation hijacks. Use simulations that start from a real email thread—because that’s what attackers are doing. - Practice Your Response
Run tabletop exercises. Can your team detect and contain this kind of compromise? Who communicates with the impacted vendor? What if the attacker starts emailing clients using your name?
In 2025, threat actors aren’t smashing through firewalls. They’re walking through the front door, wearing a name badge.
They don’t need to “hack” your systems when they can impersonate someone your team already trusts. Your security is only as strong as the relationships you depend on.
If you’re ready to strengthen your organization’s security, talk to Aldridge today. We’ll work with you to assess your risks, tighten your defenses, and make sure your team knows what to do if something goes wrong. And if you don’t already have an incident response plan in place, we’ve got you covered—download our free security incident response template to get started. Whether you need guidance or a game plan, we’re here when you need us.