Query: Lateral movement indicators for Hidden Files and Directories
Matching passage: T1564.001 Hidden Files and Directories. Tactics: stealth. Description: Adversaries may set files and directories to be hidden to evade detection mechanisms. To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (<code>dir /a</code> for Windows and <code>ls –a</code> for Linux and macOS). On Linux and Mac, users can mark specific files as hidden simply by putting a “.” as the first character in the file or folder name (Citation: Sofacy Komplex Trojan) (Citation: Antiquated Mac Malware). Files and folders that start with a period, ‘.’, are by default hidden from being viewed in the Finder application and standard command-line utilities like “ls”. Users must specifically change settings to have these files viewable. Files on macOS can also be marked with the UF_HIDDEN flag which prevents them from being seen in Finder.app, but still allows them to be seen in Terminal.app (Citation: WireLurker). On Windows, users can mark specific files as hidden by using the attrib.exe binary. Many applications create these hidden files and folders to store information so that it doesn’t clutter up the user’s workspace. For example, SSH utilities create a .ssh folder that’s hidden and contains the user’s known hosts and keys. Additionally, adversaries may name files in a manner that would allow the file to be hidden such as naming a file only a “space” character. Adversaries can use this to their advantage to hide files and folders anywhere on the system and evading a typical user or system analysis that does not incorporate investigation of hidden files.
Near-miss passage: T1564.003 Hidden Window. Tactics: stealth. 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 <code>apple.awt.UIElement</code>, 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](https://attack.mitre.org/techniques/T1059/001), Jscript, and [Visual Basic](https://attack.mitre.org/techniques/T1059/005) to make windows hidden. One example of this is <code>powershell.exe -WindowStyle Hidden</code>.(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 <code>explorer.exe</code> 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. Adversarie