Detections
Analytics

6.2.3.4 Ensure events that modify date and time information are collected

Information

Capture events where the system date and/or time has been modified. The parameters in this section are set to determine if the;

 - adjtimex - tune kernel clock
 - settimeofday - set time using timeval and timezone structures
 - clock_settime - allows for the setting of several internal clocks and timers

system calls have been executed. Further, ensure to write an audit record to the configured audit log file upon exit, tagging the records with a unique identifier such as "time-change".

Unexpected changes in system date and/or time could be a sign of malicious activity on the system.

Solution

- Edit or create a file in the /etc/audit/rules.d/ directory, ending in .rules extension, with the relevant rules to monitor events that modify date and time information.

Example:

# printf "
-a always,exit -F arch=b64 -S adjtimex,settimeofday -k time-change
-a always,exit -F arch=b32 -S adjtimex,settimeofday -k time-change
-a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -k time-change
-a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -k time-change
-w /etc/localtime -p wa -k time-change
" >> /etc/audit/rules.d/50-time-change.rules

 - Merge and load the rules into active configuration:

# augenrules --load

 - Check if reboot is required:

# if [[ $(auditctl -s | grep "enabled") =~ "2" ]]; then printf "Reboot required to load rules\n"; fi

See Also

https://workbench.cisecurity.org/benchmarks/26891

Item Details

Category: AUDIT AND ACCOUNTABILITY, CONFIGURATION MANAGEMENT

References: 800-53|AU-3, 800-53|AU-3(1), 800-53|AU-7, 800-53|AU-12, 800-53|CM-6, CSCv7|5.5

Plugin: Unix

Control ID: cdbdefa119c484b7a7b0c607a50bf1ebdd25e9fc95b504c9abdb195a0b2cfc85