System Time Discovery

What the technique is

An adversary may gather the system time and/or time zone settings from a local or remote system. The system time is set and stored by services, such as the Windows Time Service on Windows or systemsetup on macOS. These time settings may also be synchronized between systems and services in an enterprise network, typically accomplished with a network time server within a domain. System time information may be gathered in a number of ways, such as with Net on Windows by performing net time \\hostname to gather the system time on a remote system. The victim's time zone may also be inferred from the current system time or gathered by using w32tm /tz. In addition, adversaries can discover device uptime through functions such as GetTickCount() to determine how long it has been since the system booted up. On network devices, Network Device CLI commands such as show clock detail can be used to see the current time configuration. On ESXi servers, esxcli system clock get can be used for the same purpose. In addition, system calls – such as time() – have been used to collect the current time on Linux devices. On macOS systems, adversaries may use commands such as systemsetup -gettimezone or timeIntervalSinceNow to gather current time zone information or current date and time. […]

What MITRE says you would watch

• AN0430

  Untrusted or unusual process/script (cmd.exe, powershell.exe, w32tm.exe, net.exe, custom binaries) queries system time/timezone (e.g., w32tm /tz, net time \\host, Get-TimeZone, GetTickCount API) and (optionally) is followed within a short window by time-based scheduling or conditional execution (e.g., schtasks /create, at.exe, PowerShell Start-Sleep with large values).

• AN0431

  A process (often spawned by a shell, interpreter, or malware implant) executes time discovery via commands (date, timedatectl, hwclock, cat /etc/timezone, /proc/uptime) or direct syscalls (time(), clock_gettime) and is (optionally) followed by scheduled task creation/modification (crontab, at) or conditional sleep logic.

• AN0432

  Process/script execution of systemsetup -gettimezone, date, ioreg, or API usage (timeIntervalSinceNow, gettimeofday) followed by time-based scheduling (launchd plist modification) or sleep-based execution.