Detection rules › Sigma

New TimeProviders Registered With Uncommon DLL Name

Status
test
Severity
high
Log source
product windows, category registry_set
Author
frack113
Source
github.com/SigmaHQ/sigma

Detects processes setting a new DLL in DllName in under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProvider. Adversaries may abuse time providers to execute DLLs when the system boots. The Windows Time service (W32Time) enables time synchronization across and within domains.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 13RegistryEvent (Value Set)

Rule body yaml

title: New TimeProviders Registered With Uncommon DLL Name
id: e88a6ddc-74f7-463b-9b26-f69fc0d2ce85
status: test
description: |
    Detects processes setting a new DLL in DllName in under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProvider.
    Adversaries may abuse time providers to execute DLLs when the system boots.
    The Windows Time service (W32Time) enables time synchronization across and within domains.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1547.003/T1547.003.md
author: frack113
date: 2022-06-19
modified: 2024-03-26
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1547.003
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\Services\W32Time\TimeProviders'
        TargetObject|endswith: '\DllName'
    filter_main_w32time:
        Details:
            - '%SystemRoot%\System32\vmictimeprovider.dll'
            - '%systemroot%\system32\w32time.dll'
            - 'C:\Windows\SYSTEM32\w32time.DLL'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    TargetObject|contains: '\Services\W32Time\TimeProviders'
    TargetObject|endswith: '\DllName'

Stage 2: not filter_main_w32time

filter_main_w32time:
    Details:
        - '%SystemRoot%\System32\vmictimeprovider.dll'
        - '%systemroot%\system32\w32time.dll'
        - 'C:\Windows\SYSTEM32\w32time.DLL'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Detailseq%SystemRoot%\System32\vmictimeprovider.dll
Detailseq%systemroot%\system32\w32time.dll
DetailseqC:\Windows\SYSTEM32\w32time.DLL

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
TargetObjectends_with
  • \DllName
TargetObjectmatch
  • \Services\W32Time\TimeProviders