During the pandemic, collaboration apps such as Microsoft Teams and Zoom have played an important role in connecting the distributed workforce and helping organizations to cope with the so-called “new normal.” Even if we are finally starting to see the light at the end of the tunnel (and this time it’s a real light), the world won’t be exactly the same as it was before. The majority of organizations intend to embrace remote work permanently and the widespread adoption of cloud apps will continue.
Microsoft Teams claims to have more than 270 million monthly active users, and all the main collaboration apps, whether used for a personal or business purpose, have experienced a massive growth: Zoom claims to have more than 300 million daily meeting participants, and even Discord, originally conceived for gaming but now considered a full-featured collaboration app (and a safe haven for malware distribution—one of the payloads of the WhisperGate wiper malware used against Ukrainian targets was distributed from Discord) has more than 140 million active monthly users.
With these numbers, the discovery in January 2022 of a new campaign distributing malware via Microsoft Teams chat attachments is no surprise. The attackers leverage the trust in the application by the users and the fact that this traffic is normally not subject to SSL/TLS inspection, so its content can’t be inspected. This could be the ideal way to deliver malicious content in a world where collaboration apps are the new productivity tools.
It is interesting to look at the way attackers are accessing Teams:
- They can compromise a partner organization and listen in on inter-organizational chats.
- They can compromise an email address and use that address to access Teams.
- They can steal Microsoft 365 credentials from a phishing campaign (quite an effective access method considering the apparently low adoption of multi-factor authentication and the availability of troves of compromised credentials) and use the compromised credentials to gain access to different tools within the application suite.
This is yet another confirmation that the compromise of a cloud application can have multiple ramifications, providing the attackers with plenty of ammunition that they can use for their malicious purposes.
How Netskope mitigate the risk of malware distributed via Microsoft Teams (and other collaboration apps)
Microsoft Teams is one of the thousands of cloud apps for which the Cloud XD engine, the heart of the Netskope Next Gen SWG, can provide unrivaled visibility and enforce context-aware security policies.
Cloud XD can recognize dozens of activities (such as ‘Create’, ‘Delete’, ‘Edit’, ‘Invite’, ‘Join’, ‘Download’, and ‘Upload’), allowing it to govern potentially risky behaviors such as downloads from untrusted instances. Additionally, it is possible to inspect the data in motion from or to Microsoft Teams (and thousands of additional cloud apps) with the award-winning Netskope threat protection engine that provides multiple engines, including machine-learning classifiers and sandboxing to detect zero-day malware and evasive threats. The detection capabilities of the Netskope threat engine can also be integrated with additional technologies, such as endpoint protection platforms or external threat intelligence feeds through the Cloud Exchange.
A specific threat dashboard of Netskope Advanced Analytics allows real-time monitoring of the risk exposure of the organization, identification of the riskiest apps and the most targeted users, ultimately supporting the incident response and remediation process.