Blog | Apr 03, 2020

Avoid being hit by a “Zoombomb”

This week, the eSentire Threat Intelligence team released an advisory about software vulnerabilities and the hijacking of meetings in the popular Zoom™ video conferencing platform. The FBI is warning users of an uptick in “Zoombombing” during the Covid-19 pandemic, as remote workers migrate to video conferencing to stay connected.

The term refers to the hijacking of Zoom meetings to troll attendees, disseminate hateful manifestos or display pornographic material through the screen-sharing feature of the service. In specific cases, academic institutions have turned to video conferencing to provide a continuity of education, are also being targeted.

In response, Zoom has published Covid-19 resources to help customers better secure their meetings, and Zoom CEO, Eric Yuan, addressed security concerns in a blog post.

And it’s just not Zoom that’s taking heat over cybersecurity concerns. Houseparty, a popular video conferencing tool that adds the ability to remotely play games, has seen a 2000% increase in downloads during the pandemic. Houseparty are taking to social media to complain that the app led to compromises of their Netflix and Spotify accounts. These complaints have not been verified by the makers of Houseparty.

Securing your Zoom meetings

As I’ve discussed in previous Covid-19 cybersecurity-incident related posts, criminals hide in the smokescreen of the uncertainty and chaos surrounding events like a pandemic, or previous natural disasters like hurricanes Katrina and Sandy. As part of your securing your home office regimen, use the following guidelines to secure your Zoom meetings.

Keep your Zoom software up to date: Zoom is actively responding to reports of hacking and software vulnerabilities and pushes out updates that you can install through the application. Always ensure you update the software as these patches become available. It’s imperative that you keep your applications, computers and phones up to date with the latest software. These updates ensure that applications and devices maintain the strongest security profile. Applications and devices with old software often fall victim to known and defensible attacks.

Password-protect your Zoom meetings: When you organize a meeting, require a password to join. This makes it harder for unwanted guests to drop in and disrupt your call. As default, you can require a password by checking this option in the user settings. You can do the same when you create an impromptu meeting. Make sure the password option is checked. Ensure you check both the password for scheduled meetings and also for phone

Require users to be logged into Zoom to participate: For internal meetings, you should require all attendees to be logged into Zoom through their personal accounts. This should also work in most cases for external meetings. Again, this is an option in the user settings.

Enable multi-factor authentication: This is especially important for meetings in which you are discussing confidential information. Ask your Zoom administrator for help.

Lock meetings once they are running: To add another layer of security to avoid Zoombombing, consider locking the meeting once it starts. The option is available in the user settings.

Disable join before host: This is another layer of security that prevents unwanted parties from hijacking your meeting, or communicating with your participants.

Disable screen sharing: This is critical. By default, disable screen sharing in the user settings. This avoids unwanted parties displaying inappropriate content during your meeting.

Consider what’s on display: Remember, when you are on camera, there is all sorts of unintended exposure of information. Obvious examples include confidential information displayed on white boards in the background. The less obvious is knick-knacks and memorabilia, such as sports jerseys or trophies, that expose your interests. Unwanted guests can use this to socially engineer you and personalize phishing lures.

Screen participants: Whenever possible, screen your participants to look for people who don’t belong. Enforcing log-in so can you see user IDs helps.

Don’t announce meetings on social media: Never announce meetings through public venues. You wouldn’t place an ad in a newspaper inviting the general public to your house party because you won’t be able to control who shows up to take advantage (exploit) your hospitality. The same applies to Zoom meetings. Posting this information not only informs unwanted individuals of your event, but it exposes information like your meeting ID.

For more information about defending your work-from-home teams during this current global crisis: Reach out to me or visit our Covid-19 Cybersecurity Resources page.

Mark Sangster

Mark Sangster

Vice President and Industry Security Strategist

Mark is a cybersecurity evangelist who has spent significant time researching and speaking to peripheral factors influencing the way that legal firms integrate cybersecurity into their day-to-day operations.