- Tactics
- stealth
- Platforms
- Linux, macOS, Windows
- Reference
- attack.mitre.org/techniques/T1564.003
Description
Adversaries may use hidden windows to conceal malicious activity from the plain sight of users. In some cases, windows that would typically be displayed when an application carries out an operation can be hidden. This may be utilized by system administrators to avoid disrupting user work environments when carrying out administrative tasks.
Adversaries may abuse these functionalities to hide otherwise visible windows from users so as not to alert the user to adversary activity on the system.(Citation: Antiquated Mac Malware)
On macOS, the configurations for how applications run are listed in property list (plist) files. One of the tags in these files can be apple.awt.UIElement, which allows for Java applications to prevent the application’s icon from appearing in the Dock. A common use for this is when applications run in the system tray, but don’t also want to show up in the Dock.
Similarly, on Windows there are a variety of features in scripting languages, such as PowerShell, Jscript, and Visual Basic to make windows hidden. One example of this is powershell.exe -WindowStyle Hidden.(Citation: PowerShell About 2019)
The Windows Registry can also be edited to hide application windows from the current user. For example, by setting the WindowPosition subkey in the HKEY_CURRENT_USER\Console\%SystemRoot%_System32_WindowsPowerShell_v1.0_PowerShell.exe Registry key to a maximum value, PowerShell windows will open off screen and be hidden.(Citation: Cantoris Computing)
In addition, Windows supports the CreateDesktop() API that can create a hidden desktop window with its own corresponding explorer.exe process.(Citation: Hidden VNC)(Citation: Anatomy of an hVNC Attack) All applications running on the hidden desktop window, such as a hidden VNC (hVNC) session,(Citation: Hidden VNC) will be invisible to other desktops windows.
Adversaries may also leverage cmd.exe(Citation: Cybereason - Hidden Malicious Remote Access) as a parent process, and then utilize a LOLBin, such as DeviceCredentialDeployment.exe,(Citation: LOLBAS Project GitHub Device Cred Dep)(Citation: SecureList BlueNoroff Device Cred Dev) to hide windows.
How GTK Cyber trains on this
GTK Cyber's Threat Hunting with Data Science course teaches you to build machine-learning detections for techniques like this across the MITRE ATT&CK framework, including the stealth tactic this technique falls under. Practitioner-led, focused on real detections, not memorizing technique IDs.
Related techniques
- T1006 — Direct Volume Access
- T1014 — Rootkit
- T1027 — Obfuscated Files or Information
- T1036 — Masquerading
- T1055 — Process Injection
- T1070 — Indicator Removal
- T1078 — Valid Accounts
- T1127 — Trusted Developer Utilities Proxy Execution
- T1134 — Access Token Manipulation
- T1140 — Deobfuscate/Decode Files or Information
- T1197 — BITS Jobs
- T1202 — Indirect Command Execution