Query: EDR alert: possible Path Interception by PATH Environment Variable (T1574.007)
Matching passage: T1574.007 Path Interception by PATH Environment Variable. Tactics: stealth, execution. Description: Adversaries may execute their own malicious payloads by hijacking environment variables used to load libraries. The PATH environment variable contains a list of directories (User and System) that the OS searches sequentially through in search of the binary that was called from a script or the command line. Adversaries can place a malicious program in an earlier entry in the list of directories stored in the PATH environment variable, resulting in the operating system executing the malicious binary rather than the legitimate binary when it searches sequentially through that PATH listing. For example, on Windows if an adversary places a malicious program named "net.exe" in `C:\example path`, which by default precedes `C:\Windows\system32\net.exe` in the PATH environment variable, when "net" is executed from the command-line the `C:\example path` will be called instead of the system's legitimate executable at `C:\Windows\system32\net.exe`. Some methods of executing a program rely on the PATH environment variable to determine the locations that are searched when the path for the program is not given, such as executing programs from a [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059).(Citation: ExpressVPN PATH env Windows 2021) Adversaries may also directly modify the $PATH variable specifying the directories to be searched. An adversary can modify the `$PATH` variable to point to a directory they have write access. When a program using the $PATH variable is called, the OS searches the specified directory and executes the malicious binary. On macOS, this can also be performed through modifying the $HOME variable. These variables can be modified using the command-line, launchctl, [Unix Shell Configuration Modification](https://attack.mitre.org/techniques/T1546/004), or modifying the `/etc/paths.d` folder contents.(Citation: uptycs Fake POC linux malware 2023)(Citation: nixCraft macOS PATH variables)(Citation: Elastic Rules macOS launchctl 2022
Near-miss passage: T1574.008 Path Interception by Search Order Hijacking. Tactics: stealth, execution. Description: Adversaries may execute their own malicious payloads by hijacking the search order used to load other programs. Because some programs do not call other programs using the full path, adversaries may place their own file in the directory where the calling program is located, causing the operating system to launch their malicious software at the request of the calling program. Search order hijacking occurs when an adversary abuses the order in which Windows searches for programs that are not given a path. Unlike [DLL](https://attack.mitre.org/techniques/T1574/001) search order hijacking, the search order differs depending on the method that is used to execute the program. (Citation: Microsoft CreateProcess) (Citation: Windows NT Command Shell) (Citation: Microsoft WinExec) However, it is common for Windows to search in the directory of the initiating program before searching through the Windows system directory. An adversary who finds a program vulnerable to search order hijacking (i.e., a program that does not specify the path to an executable) may take advantage of this vulnerability by creating a program named after the improperly specified program and placing it within the initiating program's directory. For example, "example.exe" runs "cmd.exe" with the command-line argument <code>net user</code>. An adversary may place a program called "net.exe" within the same directory as example.exe, "net.exe" will be run instead of the Windows system utility net. In addition, if an adversary places a program called "net.com" in the same directory as "net.exe", then <code>cmd.exe /C net user</code> will execute "net.com" instead of "net.exe" due to the order of executable extensions defined under PATHEXT. (Citation: Microsoft Environment Property) Search order hijacking is also a common practice for hijacking DLL loads and is covered in [DLL](https://attack.mitre.org/techniques/T1574/001).