Delay Execution

What the technique is

Adversaries may employ various time-based methods to evade detection and analysis. These techniques often exploit system clocks, delays, or timing mechanisms to obscure malicious activity, blend in with benign activity, and avoid scrutiny. Adversaries can perform this behavior within virtualization/sandbox environments or natively on host systems. Adversaries may utilize programmatic sleep commands or native system scheduling functionality, for example Scheduled Task/Job. Benign commands or other operations may also be used to delay malware execution or ensure prior commands have had time to execute properly. Loops or otherwise needless repetitions of commands, such as ping, may be used to delay malware execution and potentially exceed time thresholds of automated analysis environments. Another variation, commonly referred to as API hammering, involves making various calls to Native API functions in order to delay execution (while also potentially overloading analysis environments with junk data).

What MITRE says you would watch

• AN1048

  Correlated use of sleep/delay mechanisms (e.g., kernel32!Sleep, NTDLL APIs) in short-lived processes, combined with parent processes invoking suspicious scripts (e.g., wscript, powershell) with minimal user interaction.

• AN1049

  Shell scripts or binaries invoking repeated 'sleep', 'ping', or low-level syscalls (e.g., nanosleep) in short-lived execution chains with no user or system interaction. Frequently seen in malicious cron jobs or payload stagers.

• AN1050

  Execution of AppleScript, bash, or launchd jobs that invoke delay functions (e.g., sleep, delay in AppleScript) with limited parent interaction and staged follow-on commands.