Discovery of a System Time

Status: test
Severity: low
Log source: category process_creation, product windows
Author: E.M. Anhaus (originally from Atomic Blue Detections, Endgame), oscd.community
Source: github.com/SigmaHQ/sigma

Identifies use of various commands to query a systems time. This technique may be used before executing a scheduled task or to discover the time zone of a target system.

Known false positives

Legitimate use of the system utilities to discover system time for legitimate reason

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1124` System Time Discovery

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Discovery of a System Time
id: b243b280-65fe-48df-ba07-6ddea7646427
status: test
description: Identifies use of various commands to query a systems time. This technique may be used before executing a scheduled task or to discover the time zone of a target system.
references:
    - https://eqllib.readthedocs.io/en/latest/analytics/fcdb99c2-ac3c-4bde-b664-4b336329bed2.html
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1124/T1124.md
author: E.M. Anhaus (originally from Atomic Blue Detections, Endgame), oscd.community
date: 2019-10-24
modified: 2022-06-28
tags:
    - attack.discovery
    - attack.t1124
logsource:
    category: process_creation
    product: windows
detection:
    selection_time:
        Image|endswith:
            - '\net.exe'
            - '\net1.exe'
        CommandLine|contains: 'time'
    selection_w32tm:
        Image|endswith: '\w32tm.exe'
        CommandLine|contains: 'tz'
    condition: 1 of selection_*
falsepositives:
    - Legitimate use of the system utilities to discover system time for legitimate reason
level: low

Stages and Predicates

Stage 0: `condition`

1 of selection_*

Stage 1: `selection_time`

selection_time:
    Image|endswith:
        - '\net.exe'
        - '\net1.exe'
    CommandLine|contains: 'time'

Stage 2: `selection_w32tm`

selection_w32tm:
    Image|endswith: '\w32tm.exe'
    CommandLine|contains: 'tz'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`time` `tz`	`field:"CommandLine" kind:match`
`Image`	ends_with	`\net.exe` corpus 49 (sigma 49) `\net1.exe` corpus 47 (sigma 47) `\w32tm.exe` corpus 2 (sigma 2)	`field:"Image" kind:ends_with`