The Message That Started It All
Picture this.
It’s 9:47 AM on a Tuesday. You’re halfway through your second cup of coffee, trying to ignore the blinking Teams icon begging for attention. A message pops up from your boss.
“Hey, can you process that payment real quick before lunch? $10,000, same vendor as last month.”
Seems legit. Same tone. Same name. Same photo of your boss smiling awkwardly at last year’s Christmas party.
You hover over the chat bubble, nod once, and start typing back.
Only, here’s the thing… your boss didn’t send that.
That’s the reality Microsoft Teams users found themselves facing after researchers uncovered a set of security bugs that allowed imposters to edit messages, fake names, and send completely fabricated chats without leaving a trace.
And for a platform that 320 million people rely on every day to share files, approve purchases, and coordinate entire companies, that’s a pretty big “oops.”
Welcome to the New Phishing Playground
For years, phishing has lived in email inboxes. It’s where we expect it, where filters are built, and where staff are trained to spot it.
But now it’s moving into chat.
That’s what made these Microsoft Teams vulnerabilities so dangerous. They didn’t just break a feature. They broke trust.
Researchers at Check Point found that certain bugs in Teams let bad actors:
- Edit messages without showing “Edited.”
- Change who appeared to send them.
- Modify notifications to spoof the sender.
- Even change display names during calls.
In other words, Teams briefly became a perfect stage for digital impersonation.
Imagine you’re in accounting and you get a DM that looks like it came from the CFO asking for vendor wire details. Or you’re in HR, and someone “from IT” messages you asking you to verify your login for an audit.
Same profile photo. Same writing style. Zero suspicion.
That’s how phishing evolves. It doesn’t break through a firewall. It walks in through trust.
“But It’s Internal, So It’s Safe!”
The most common phrase in every small business: “Oh, that’s internal. It’s safe.”
That line might have worked ten years ago, but now internal doesn’t mean invincible.
Every MSP in the country has seen this pattern:
- A compromised Microsoft 365 account sends messages internally.
- The other employees click or comply because the message came from “inside the house.”
- The attacker doesn’t need to phish outsiders anymore. They can live off your internal chat history, invoices, and good intentions.
This Teams flaw just threw gasoline on that fire.
Because once an attacker can fake who’s speaking, it doesn’t matter how secure your passwords or backups are. They’ve already hacked the one thing you can’t patch: human trust.
Microsoft’s Response (and What It Really Means)
Microsoft did respond and patch the vulnerabilities… eventually.
One of them, CVE-2024-38197, was fixed back in August 2024. Others trickled out through September 2024 and October 2025.
If you’re keeping score, that’s a 19-month timeline from disclosure to full mitigation. Not terrible by corporate standards, but it’s a lifetime in hacker time.
The company described the flaw blandly as a “medium-severity spoofing issue.”
Translation: a hacker could pretend to be your coworker, get you to do something dumb, and nobody would know until it was too late.
To be fair, this wasn’t a data-stealing exploit. It was worse: a social engineering amplifier.
And Microsoft isn’t alone. Slack, Zoom, Webex, Google Chat… they’ve all had impersonation vulnerabilities in the last few years. Because collaboration platforms are where the business actually happens.
If email was the front door, chat is the hallway.
And hackers just figured out how to sound like your boss from down the hall.
The Psychology of Fake Authority
Let’s step back from the tech for a second.
Why does this even work? Why do people still click, approve, or send money even when every cybersecurity training says “Don’t”?
Because authority is the fastest shortcut in the human brain.
When we see a name we trust, like a manager, a coworker, a client… our logical brain shuts off. We stop analyzing and start cooperating.
It’s called social proof.
And collaboration tools like Teams are built on it. The entire interface reinforces identity: profile pictures, colored initials, timestamps, green “Available” dots. Everything screams “this person is real.”
So when that trust layer gets hijacked, it’s not just a security issue. It’s a psychological one.
Attackers know this. That’s why they write messages that feel rushed (“Need this done ASAP!”) or personal (“Hey, can you help me out real quick?”).
The faster they get you to act, the less time you have to think.
That’s the real danger behind these Teams flaws. They didn’t just let hackers fake messages. They let them weaponize familiarity.
How It Looks in the Real World
Let’s play this out.
You’re the office manager for a medical practice. You handle invoices and ordering. You get a Teams message from “Dr. Patel”:
“Hey, quick favor… can you send over the bank routing info for the new vendor account? I’m in meetings all day.”
You respond immediately because Dr. Patel is always slammed with patients and never emails.
You attach the info. He says thanks.
An hour later, the real Dr. Patel messages you asking why accounting just sent out a $22,000 wire.
That’s not hypothetical. That’s happened.
In one incident I dealt with personally, a compromised Teams account was used to schedule a fake meeting with a staff member. The attacker joined the call, turned off their camera, and pretended to be a vendor rep confirming payment details.
They didn’t hack a system. They hacked a moment.
The Bigger Pattern: Trust as the New Attack Surface
For decades, cybersecurity focused on keeping the bad guys out. Firewalls, antivirus, spam filters, MFA.
Now the threat isn’t “out there.” It’s inside your collaboration tools.
Hackers realized they don’t need to brute-force anything when they can just borrow your logo, your tone, and your habits.
And that’s the pattern we keep seeing:
- Deepfake voice calls where the “CEO” requests funds.
- AI-written messages mimicking coworkers’ writing styles.
- Compromised Teams or Slack accounts used to drop malware links.
- Fake support staff joining group chats and offering to “help.”
All of it leverages one idea: the easiest way to hack a business is to make them trust you first.
That’s why this Teams issue matters so much. It’s not about one patch or one app. It’s about realizing that trust itself is now part of your security perimeter.
“But We’re a Small Business. Nobody Would Target Us.”
If I had a dollar for every time I’ve heard that…
Well, I’d have roughly as much as the scammers asking for $10,000 on Teams.
The truth: small businesses are prime targets precisely because they think they’re not.
Attackers know you don’t have a 24/7 SOC or a dedicated IT department watching every log. They know your bookkeeper uses the same password for QuickBooks and email.
And they know your team lives inside chat tools like Teams.
Here’s a hard truth… the smaller your business, the more powerful one fake message becomes. Because in a ten-person company, one person usually wears five hats. If that one person gets tricked, every hat catches fire.
So What Should You Actually Do?
Let’s break this down into practical, no-nonsense steps.
1. Verify high-risk requests outside the chat window
Money, credentials, data… if it matters, confirm it on another channel. Call, text, or walk over. Old-school verification beats new-school deception.
2. Keep Teams and Office apps updated
Yes, it’s annoying. Yes, it feels endless. But those “Update now” buttons exist for a reason. The people exploiting these bugs love lazy patch cycles.
3. Train staff to spot behavioral weirdness
It’s not about links or grammar anymore. It’s about tone, urgency, and context. If your usually-formal manager suddenly types “Hey buddy,” that’s your red flag.
4. Implement behavioral-based monitoring
Tools like Huntress, Barracuda Sentinel, or Microsoft Defender for Business can detect anomalies, such as a login from another country or a Teams session sending messages outside normal patterns.
5. Set up conditional access
Make sure users can’t log into Teams from unapproved or risky devices. Pair it with MFA and device compliance.
6. Don’t store credentials or sensitive files in chat
That one’s simple. Chat is convenient, not secure storage. Keep confidential info in proper systems with access controls.
7. Run internal phishing drills that include chat apps
Email drills are old news. Start simulating fake Teams messages. The results will be eye-opening.
Why Microsoft Can’t Fix Human Nature
To be fair, Microsoft has a near-impossible job. Teams isn’t just a chat app anymore. It’s a platform glued into SharePoint, Outlook, OneDrive, Viva, and half the corporate world.
Fixing every trust loophole would mean redesigning how collaboration itself works.
So Microsoft does what every tech giant does: patches the code and calls it a day.
But that leaves business owners holding the bag. Because no matter how many updates come out, you can’t patch people.
That’s where culture comes in.
Teach your team that it’s okay to question things that look legit.
Normalize asking, “Hey, did you really send this?”
Reward caution, not speed.
Because the day your bookkeeper hesitates instead of clicks, that’s the day you win.
The MSP’s Reality Check
From my side of the screen, running an MSP means watching clients walk a tightrope between convenience and chaos.
Everyone wants the shiny new tool until it burns them.
Everyone wants security until it slows them down.
This Teams issue is a perfect example of that tension. Businesses rely on instant messaging because it’s fast, informal, and easy. But those same qualities make it dangerous when trust gets bent.
When we deploy or support Teams for clients, we always remind them:
“It’s not your chat app that’s safe. It’s your habits that are.”
You can’t outsource trust. You can only manage it.
“Okay Erik, But Be Honest.. Should I Be Worried?”
Yes… but not panicked.
The bug is patched. The danger isn’t.
Think of it like this: Microsoft closed one specific door, but there are still a thousand windows labeled “Human Nature.”
What this should do is change how you think about trust in your digital tools.
It’s not about paranoia. It’s about pattern recognition.
You lock your office at night. You verify who’s on your network. Do the same for the people in your chat.
A healthy dose of skepticism can save you a lot of pain.
Real Talk: The Future of Business Chat
Let’s zoom out.
The next wave of business security isn’t about new firewalls. It’s about context verification.
AI-driven systems are starting to flag tone changes, detect identity inconsistencies, and alert when a message style doesn’t match previous writing patterns.
That’s good… but we’re not there yet.
Until then, the best defense remains awareness, not automation.
Think of chat the same way you think of money. You don’t hand it to anyone who looks trustworthy. You check ID first.
Same goes for Teams, Slack, or whatever we’ll be using next year.
A Quick Geek³ PSA
If you’re reading this as a Geek³ client:
Your systems are monitored, your patches are handled, and we stay on top of these disclosures so you don’t have to.
But education is still your best defense.
Every employee who learns to question the little things… the sudden tone shift, the weird urgency, the “send me $10,000” message adds a layer of security no software can match.
Security doesn’t start in a server rack. It starts between your ears.
The Takeaway
The Teams impersonation bug is more than a technical hiccup. It’s a warning shot.
Collaboration tools are the new battleground, and trust is the new perimeter.
The next phishing attack might not come in through your inbox. It might show up right next to the “good morning” GIF, pretending to be your coworker.
So before you hit “Send,” pause for half a second.
Ask yourself: Would Karen from Accounting really say that?
Because if not… maybe hold off on sending that wire, that password, or that meme.
