Detect Time Based Checks in CrowdStrike LogScale
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/
LogScale Detection Query
#event_simpleName = "ProcessRollup2"
| CommandLine = /(?i)(gettickcount|getsystemtimeasfiletime|queryperformancecounter|ntquerysystemtime|timegettime|getsystemtime|start-sleep|wscript\.sleep|thread\.sleep|lastbootuptime|net\s+statistics)/
OR (FileName = /(?i)^timeout\.exe$/ AND CommandLine = /\/t\s+\d{3,}/)
OR (FileName = /(?i)^ping\.exe$/ AND CommandLine = /-n\s+\d{3,}\s+127\.0\.0\.1/)
| TimingAPICheck := if(CommandLine =~ /(?i)(gettickcount|getsystemtimeasfiletime|queryperformancecounter|ntquerysystemtime|timegettime|getsystemtime)/, 2, 0)
| LongTimeout := if(FileName =~ /(?i)^timeout\.exe$/ AND CommandLine =~ /\/t\s+\d{3,}/, 2, 0)
| LongPingSleep := if(FileName =~ /(?i)^ping\.exe$/ AND CommandLine =~ /-n\s+\d{3,}\s+127\.0\.0\.1/, 2, 0)
| ScriptSleep := if(CommandLine =~ /(?i)(start-sleep|wscript\.sleep|thread\.sleep)/, 1, 0)
| UptimeQuery := if(CommandLine =~ /(?i)(lastbootuptime|net\s+statistics)/, 1, 0)
| SuspicionScore := TimingAPICheck + LongTimeout + LongPingSleep + ScriptSleep + UptimeQuery
| SuspicionScore > 0
| select([@timestamp, ComputerName, UserName, FileName, CommandLine, ParentBaseFileName, ParentCommandLine, TimingAPICheck, LongTimeout, LongPingSleep, ScriptSleep, UptimeQuery, SuspicionScore])
| sort(timestamp, order=desc)CrowdStrike Falcon LogScale (CQL) query detecting T1497.003 time-based evasion via ProcessRollup2 telemetry events. Filters on timing API strings, long sleep invocations via timeout.exe or ping.exe, scripting language sleep calls, and uptime enumeration commands. Computes a composite suspicion score to prioritize high-confidence hits. Requires Falcon Prevent or Insight with process telemetry enabled.
Data Sources
Required Tables
False Positives & Tuning
- IT automation frameworks (Ansible WinRM, Puppet, SaltStack) executing sleep-based retry logic via PowerShell or cmd on managed Windows endpoints
- Software installers (e.g., Visual Studio redistributables, SQL Server setup) using ping-based delays to wait for services to initialize
- Windows Performance Toolkit or custom benchmarking scripts invoking QueryPerformanceCounter for timing measurements passed as command-line arguments
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
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