Detect Time Based Checks in Google Chronicle
Adversaries may employ various time-based methods to detect virtualization and analysis environments, particularly those that attempt to manipulate time mechanisms to simulate longer elapses of time. This includes using GetTickCount and GetSystemTimeAsFileTime to detect time acceleration in sandboxes, implementing long sleep delays (minutes to hours) to outlast sandbox analysis timeouts, checking system uptime to verify the machine has been running for a reasonable period, computing execution timing differences before and after sleep to detect sandbox time manipulation, and using API hammering (excessive printf or I/O calls) to delay execution. Notable examples include SUNBURST (2-week dormancy), Ursnif (30-minute delay), Bumblebee (hardcoded and randomized sleep intervals), and TrickBot (printf-based API hammering).
MITRE ATT&CK
- Tactic
- Defense Evasion Discovery
- Technique
- T1497 Virtualization/Sandbox Evasion
- Sub-technique
- T1497.003 Time Based Checks
- Canonical reference
- https://attack.mitre.org/techniques/T1497/003/
YARA-L Detection Query
rule t1497_003_time_based_evasion {
meta:
author = "Detection Engineering"
description = "Detects T1497.003 time-based sandbox evasion: timing API calls, long sleep delays via timeout/ping, scripting sleep functions, and system uptime enumeration"
mitre_attack_tactic = "Defense Evasion"
mitre_attack_technique = "T1497.003"
mitre_attack_url = "https://attack.mitre.org/techniques/T1497/003/"
severity = "MEDIUM"
confidence = "MEDIUM"
version = "1.0"
events:
$e.metadata.event_type = "PROCESS_LAUNCH"
(
re.regex($e.principal.process.command_line, `(?i)(gettickcount|getsystemtimeasfiletime|queryperformancecounter|ntquerysystemtime|timegettime|getsystemtime)`) or
(
re.regex($e.principal.process.file.full_path, `(?i)\\timeout\.exe$`) and
re.regex($e.principal.process.command_line, `/t\s+\d{3,}`)
) or
(
re.regex($e.principal.process.file.full_path, `(?i)\\ping\.exe$`) and
re.regex($e.principal.process.command_line, `-n\s+\d{3,}\s+127\.0\.0\.1`)
) or
(
re.regex($e.principal.process.command_line, `(?i)(start-sleep|wscript\.sleep|thread\.sleep)`) and
not re.regex($e.principal.process.parent_process.file.full_path, `(?i)(svchost\.exe|explorer\.exe|taskhostw\.exe)$`)
) or
re.regex($e.principal.process.command_line, `(?i)(lastbootuptime|net\s+statistics)`)
)
condition:
$e
}Chronicle YARA-L 2.0 rule detecting T1497.003 time-based virtual environment detection techniques. Matches PROCESS_LAUNCH UDM events containing timing API strings, long timeout.exe or ping.exe delay invocations, scripting language sleep functions, and system uptime queries. Excludes known-benign parent processes for sleep-command detections to reduce false positives.
Data Sources
Required Tables
False Positives & Tuning
- Automated patch management systems querying lastbootuptime to determine whether a reboot is required after updates
- PowerShell Desired State Configuration (DSC) scripts using Start-Sleep for convergence delays between resource applications
- Security assessment and benchmarking tools referencing QueryPerformanceCounter or GetTickCount in process arguments during performance tests
Other platforms for T1497.003
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Extended timeout delay for sandbox evasion
Expected signal: Sysmon Event ID 1: Process Create for timeout.exe with '/t 180' argument. The process will be visible in task list for the duration of the delay. Security Event ID 4688 with command line.
- Test 2Ping-based sleep for sandbox evasion
Expected signal: Sysmon Event ID 1: Process Create for ping.exe with '-n 300 127.0.0.1' arguments. Sysmon Event ID 3: Network Connection events to 127.0.0.1 (loopback).
- Test 3WMI uptime check for sandbox detection
Expected signal: Sysmon Event ID 1: Process Create for wmic.exe with 'os get lastbootuptime' arguments. WMI Operational log entry for Win32_OperatingSystem query.
References (6)
- https://attack.mitre.org/techniques/T1497/003/
- https://www.isaca.org/resources/isaca-journal/issues/2017/volume-6/evasive-malware-tricks-how-malware-evades-detection-by-sandboxes
- https://www.fireeye.com/blog/threat-research/2020/12/evasive-attacker-leverages-solarwinds-supply-chain-compromises-with-sunburst-backdoor.html
- https://www.welivesecurity.com/2019/07/okrum-ke3chang-malware/
- https://unit42.paloaltonetworks.com/atoms/bendybear/
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1497.003/T1497.003.md
Unlock Pro Content
Get the full detection package for T1497.003 including response playbook, investigation guide, and atomic red team tests.