Teams.exe

Commands

1. ExecuteUser T1218.015

   Execute JavaScript code

   teams.exe

   Generate JavaScript payload and package.json, and save to “%LOCALAPPDATA%\Microsoft\Teams\current\app\” before executing.

   os: Windows 10, Windows 11

   Execute: Node.JS

2. ExecuteUser T1218.015

   Execute JavaScript code

   teams.exe

   Generate JavaScript payload and package.json, archive in ASAR file and save to “%LOCALAPPDATA%\Microsoft\Teams\current\app.asar” before executing.

   os: Windows 10, Windows 11

   Execute: Node.JS

3. ExecuteUser T1218.015

   Executes a process under a trusted Microsoft signed binary

   teams.exe --disable-gpu-sandbox --gpu-launcher="{CMD} &&"

   Teams spawns cmd.exe as a child process of teams.exe and executes the ping command

   os: Windows 10, Windows 11

   Execute: CMD

Detection

• IOC%LOCALAPPDATA%\Microsoft\Teams\current\app directory created
• IOC%LOCALAPPDATA%\Microsoft\Teams\current\app.asar file created/modified by non-Teams installer/updater
• Sigma https://github.com/SigmaHQ/sigma/blob/43277f26fc1c81fc98fc79147b711189e901b757/rules/windows/process_creation/proc_creation_win_susp_electron_exeuction_proxy.yml

Code samples

• https://github.com/lltltk/LOLBAS-research/tree/master/Teams

Resources

• https://l--k.uk/2022/01/16/microsoft-teams-and-other-electron-apps-as-lolbins/