Malicious, re-packaged versions of the Zoom video conferencing application are targeting work-from-home Android users with adware and Trojans, Bitdefender reports.
Forced by the current COVID-19 pandemic to work from home, many are using Zoom to stay connected with co-workers and other people they work with, and cybercriminals are taking advantage of the situation to trick people into downloading their malicious programs.
Zoom has become of increased interest over the past several weeks, not only due to the spike in usage, but also because of various security and privacy issues that impact it and its users.
Despite that, millions are using it for video conferencing purposes, which cyber-criminals are seeing as an opportunity for performing malicious activities.
One type of attack, Bitdefender reveals, involves the use of re-packaged Zoom clones that are being distributed via third-party markets. The observed samples only target users who sideload applications and have never made it to Google Play.
Featuring a user interface identical to the original application, one of the re-packaged programs also keeps the same package name as the original, and nearly identical certificate details.
The software was designed to download a payload from its command and control infrastructure at tcp[:]//googleteamsupport[.]ddns.net:4444.
The domain is a “dynamic DNS service that allows a user with a dynamic IP address to map it to a subdomain, so they can offer a service without interruption, even when their dynamic IP address changes,” Bitdefender explains.
The security firm was able to link the subdomain to sweetman2020[.]no-ip[.]biz, which was used as a C&C server for the Android remote access Trojan (RAT) known as SandoRAT and DroidJack.
Another injected Zoom application was observed specifically targeting Chinese users. Once installed, the app requests phone, location and photo permissions. The software was designed to display ads to victims, but only for a second.
A third malicious sample that attempts to impersonate Zoom is targeting Android users in the United States, Bitdefender says. Named ZOOM Cloud Meetings, the application hides itself from the menu after execution, then starts a repeating alarm that randomly sends intent to an ad service to open an ad.
The malicious app then checks for a hardcoded string in assets, called ‘admin’, and asks for admin rights if the string is true. If not, it attempts to download another file when launched.
The sample can ask for device admin permissions in English or Russian, depending on the device’s default language. It can also start itself when the device is powered on, Bitdefender says.