ESXi System Clock Manipulation
Last updated 2 days ago on 2026-07-17
About
This detection identifies a significant change to the system clock on an ESXi host, which may indicate an attempt to manipulate timestamps and evade detection or forensic analysis
- Platform
Splunk
- Tags
- Data Source: SplunkDomain: ApplicationRule Type: QueryOS: Any
- Severity
- medium
- Risk Score
- 47
- False Positives
- Limited false positives in most environments, however tune as needed
- Source
- View on GitHub(external, opens in a new tab or window)
Definition
- Rule Language
- SPL
- Rule Type
- query
text code block:`esxi_syslog` Message="*NTPClock*" AND Message="*system clock stepped*" | rex field=_raw "stepped to (?<epoch_time>\d+\.\d+),.+delta\s(?<delta>\d+)\s" | rex field=_raw "Z (?<dest>[\w\.]+)\s" | eval epoch_time=tonumber(epoch_time) | eval delta=tonumber(delta) | eval event_time=round(_time, 0) | eval direction=if(epoch_time < event_time, "backward", "forward") | eval original_time=if(direction=="backward", epoch_time + delta, epoch_time - delta) | eval stepped_to_str=strftime(epoch_time, "%Y-%m-%d %H:%M:%S") | eval original_time_str=strftime(original_time, "%Y-%m-%d %H:%M:%S") | stats min(_time) as firstTime max(_time) as lastTime count by dest direction original_time_str stepped_to_str epoch_time delta | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_system_clock_manipulation_filter`
View this rule on Splunk
This rule was sourced from the official Splunk public repository. View the original rule on GitHub(external, opens in a new tab or window).