Recently, threat actors have been exploiting Microsoft Teams to target employees within organizations. By creating fake external accounts, these cybercriminals impersonate the corporate IT help desk and send messages that appear to be from legitimate sources. They typically claim to be reaching out to help resolve issues related to spam, malware, or other security concerns.
In many cases, the attackers attempt to gain the employee's trust by offering to resolve email problems, enhance account security, or perform system maintenance. They may use tactics such as encouraging employees to click on malicious links, download infected files, or provide sensitive information, including login credentials or multi-factor authentication codes, all under the pretense of offering support.
This form of social engineering preys on the familiarity and trust employees have in communications from internal IT teams, especially when those messages seem to come from a trusted source like the help desk. With Microsoft Teams becoming an increasingly popular platform for collaboration, attackers are taking advantage of its widespread use to circumvent traditional email security measures and other defenses.
Flowchart: Microsoft Teams Impersonation Attack
Key Tactics in the Infection Chain:
Impersonation: Attackers pose as a trusted entity, such as the IT help desk, to gain the victim’s confidence and make the communication seem legitimate.
Phishing: Victims are tricked into clicking malicious links or downloading infected files, often leading to credential theft or malware installation.
Exploiting Urgency and Authority: Cybercriminals create a sense of urgency or leverage the perceived authority of IT to prompt immediate action, reducing the victim’s ability to critically assess the situation.
Multi-Stage Exploitation: The attackers use a combination of credential theft, malware deployment, and remote access tools to escalate the attack, gain deeper access, and further compromise the system or network.
Recommendations:
Monitor Teams Activity: Regularly monitor Teams for suspicious messages from external accounts and set up alerts to block unauthorized users. Review Teams settings to ensure secure configurations.
Restrict External User Access: Limit external user communication in Teams to trusted partners only, reducing the risk of impersonation attacks.
Use Endpoint Protection & Email Filtering: Deploy strong endpoint security (anti-virus, anti-malware) on all devices and configure email filters to block phishing attempts, malicious links, and attachments before they reach employees.
Happy Learning and Be Aware!!