From Mailbox to Chatbox: Cybercriminals Are Using Microsoft Teams to Exploit Your Employees
Published on: 25 Apr 2025
Last modified on: 29 Jul 2026
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As organisations shift to Microsoft Teams for day-to-day communication and collaboration, cybercriminals are following close behind—exploiting the platform’s trusted environment to bypass traditional security barriers.
No longer confined to email inboxes, phishing and malware threats are now being delivered directly through Teams chats, often under the guise of legitimate internal communication.
How Cybercriminals Are Targeting Microsoft Teams Users
- Multi-Stage Malware Attacks: Sophisticated campaigns have been observed using Microsoft Teams to deliver malware via links or attachments, including techniques like DLL sideloading.
- IT Impersonation: In one notable incident, attackers posed as IT staff on Teams, convincing employees to grant remote access—ultimately resulting in ransomware deployment.
- Malicious File Sharing: Attackers have distributed malware through Teams by disguising it as harmless files like PDFs, exploiting users’ trust in internal systems. These strategies exploit the inherent trust employees place in internal communication tools, making them particularly effective.
Why Microsoft Teams Is an Appealing Attack Vector
Several factors contribute to Teams becoming a favoured vector for cyberattacks:
- Trusted Environment: Employees often perceive Microsoft Teams as a secure, internal platform, leading to reduced scrutiny of messages and attachments.
- External Access Features: Teams’ capability to allow messages from external users can be misused by attackers to impersonate trusted contacts.
- Lack of Awareness: Many organisations focus security training on email threats, leaving a gap in awareness regarding risks associated with collaboration tools.
How to Defend Against Teams-Based Threats
To mitigate these risks, organisations should:
- Expand Security Training: Incorporate scenarios involving Teams-based phishing in security awareness programmes to educate employees on recognising and responding to such threats.
- Review and Adjust Settings: Regularly assess Teams’ external access configurations to ensure they align with the organisation’s security policies and risk tolerance.
- Promote a Culture of Vigilance: Encourage employees to verify unexpected messages – especially those requesting sensitive information or access, regardless of the platform used.
Ready to Strengthen Your Defences Against Teams-Based Threats?
Cybercriminals are no longer knocking on your email inbox—they’re sliding into your Teams chat. As the threat landscape evolves, so must your defences.
By expanding employee awareness, implementing phishing simulation platforms tailored to collaboration tools like Microsoft Teams, and delivering focused security awareness training, your organisation can stay one step ahead of these emerging threats.
Don’t wait for an incident to take action. Proactive education, continuous testing, and smarter platform controls are essential to reducing risk and building a cyber-resilient culture. Whether you’re looking to simulate real-world attacks, strengthen user awareness, or tighten Teams security configurations—we’re here to help. Get in touch today to build a tailored campaign that meets your organisation’s unique needs.
Frequently Asked Questions About Microsoft Teams Phishing
Can phishing attacks happen through Microsoft Teams?
Yes. Cybercriminals increasingly use Microsoft Teams to deliver phishing messages, malicious links and fake IT support requests. Because employees often trust collaboration platforms more than email, these attacks can be highly effective.
What are the warning signs of a Microsoft Teams phishing attack?
Warning signs include unexpected messages requesting sensitive information, urgent requests for passwords or remote access, unfamiliar external contacts, suspicious links or attachments, and messages encouraging immediate action without verification.
Why do cyber criminals use Microsoft Teams for phishing?
Attackers use Microsoft Teams because it is widely trusted within organisations. Employees may be less suspicious of messages received through collaboration tools than traditional emails, making Teams an attractive platform for phishing and social engineering attacks.
Can a Microsoft Teams message contain malware?
Yes. Malware can be delivered through malicious file attachments, links to compromised websites or downloads disguised as legitimate documents. Employees should treat unexpected files or links in Teams with the same caution they would apply to suspicious emails.
What should an employee do after receiving a suspicious Teams message?
Employees should avoid clicking links or opening attachments, verify unexpected requests through a trusted communication channel, report the message to their IT or security team and delete it once it has been investigated.
Regular Security Awareness Training and Advanced Phishing Simulation exercises help employees recognise these attacks before they become security incidents.
Book a demo to see how MetaCompliance can help prepare your workforce for threats across email, Microsoft Teams and other collaboration platforms.