The getuid system call is used to obtain the real user ID of the calling process. It's a fundamental part of Unix-like operating systems, providing a way for processes to identify the user who executed them.
Regularly monitor and audit the use of administrator privileges and sensitive commands. This helps detect unauthorized access or misuse.
Summary
Pros
Cons
When to require administrator privileges
Alternatives and mitigations
Recommendations
Verdict Requiring administrator privileges for getuidx64 can be justified when full, authoritative system-level identifiers are required (auditing, forensics, system management). However, prefer a design that minimizes elevation, documents requirements clearly, and implements safeguards to reduce security and operational downsides. getuidx64 require administrator privileges better
The "x64" suffix implies a compiled binary for 64-bit architectures. On modern x64 Windows systems with features like Kernel Patch Protection (PatchGuard), user-mode tools often rely on specific drivers or deep system calls to gather certain identifiers.
Loading drivers or interacting with the kernel memory space requires elevation. If getuidx64 attempts to resolve kernel callbacks or walk system structures manually to find user identifiers (a technique common in advanced EDR evasion), it must be Elevated.
| Feature | Unix/Linux | Windows NT (x64) |
|---------|-------------|------------------|
| User identifier | uid_t (integer) | SID (variable-length structure) |
| Process token | Implicit per process | Explicit HANDLE to an ACCESS_TOKEN |
| API to get caller’s UID | getuid() – no handle needed | OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, ...) |
| Privilege required | None | TOKEN_QUERY – usually granted to all processes, but... |
The key nuance: TOKEN_QUERY is typically available to any process for its own token. So why does a custom getuidx64 sometimes require admin? The getuid system call is used to obtain
To strictly require and verify administrator privileges in an x64 environment, you must check if the EUID is 0.
Many cross-platform porting tools embed a requested execution level of requireAdministrator in their manifest file, even for simple queries. This is defensive programming: the developer didn’t want to handle partial failures when getuidx64 attempts to read /etc/passwd-style files that don’t exist on Windows.
Better approach: Recompile with asInvoker and fix the underlying SID resolution logic.
Some broken implementations try to get the “real” user identity by walking parent processes (e.g., to bypass CreateProcessAsUser). To open the token of another process, you need: system management). However