Imports Registry Key From a File

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Oddvar Moe, Sander Wiebing, oscd.community
Source: github.com/SigmaHQ/sigma

Detects the import of the specified file to the registry with regedit.exe.

Known false positives

Legitimate import of keys
Evernote

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1112` Modify Registry
Defense Impairment	`T1112` Modify Registry

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

title: Imports Registry Key From a File
id: 73bba97f-a82d-42ce-b315-9182e76c57b1
related:
    - id: 0b80ade5-6997-4b1d-99a1-71701778ea61
      type: similar
status: test
description: Detects the import of the specified file to the registry with regedit.exe.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/Regedit/
    - https://gist.github.com/api0cradle/cdd2d0d0ec9abb686f0e89306e277b8f
author: Oddvar Moe, Sander Wiebing, oscd.community
date: 2020-10-07
modified: 2024-03-13
tags:
    - attack.persistence
    - attack.defense-impairment
    - attack.t1112
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\regedit.exe'
        - OriginalFileName: 'REGEDIT.EXE'
    selection_cli:
        CommandLine|contains:
            - ' /i '
            - ' /s '
            - '.reg'
    filter_1:
        CommandLine|contains|windash:
            - ' -e '
            - ' -a '
            - ' -c '
    filter_2:
        CommandLine|re: ':[^ \\]'     # to avoid intersection with ADS rule
    condition: all of selection_* and not all of filter_*
falsepositives:
    - Legitimate import of keys
    - Evernote
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_* and not all of filter_*

Stage 1: `selection_img`

selection_img:
    - Image|endswith: '\regedit.exe'
    - OriginalFileName: 'REGEDIT.EXE'

Stage 2: `selection_cli`

selection_cli:
    CommandLine|contains:
        - ' /i '
        - ' /s '
        - '.reg'

Stage 3: `not filter_1`

filter_1:
    CommandLine|contains|windash:
        - ' -e '
        - ' -a '
        - ' -c '

Stage 4: `not filter_2`

filter_2:
    CommandLine|re: ':[^ \\]'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`CommandLine`	match	`-a`	`excludes:CommandLine` `field:"CommandLine" value:" -a "`
`CommandLine`	match	`-c`	`excludes:CommandLine` `field:"CommandLine" value:" -c "`
`CommandLine`	match	`-e`	`excludes:CommandLine` `field:"CommandLine" value:" -e "`
`CommandLine`	regex_match	`:[^ \]`	`excludes:CommandLine` `field:"CommandLine" value:":[^ \]"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`/i` corpus 2 (sigma 2) `/s` corpus 6 (sigma 3, splunk 3) `.reg` corpus 4 (sigma 3, splunk 1)	`field:"CommandLine" kind:match`
`Image`	ends_with	`\regedit.exe` corpus 8 (sigma 8)	`field:"Image" kind:ends_with value:"\regedit.exe"`
`OriginalFileName`	eq	`REGEDIT.EXE` corpus 6 (sigma 4, splunk 2)	`field:"OriginalFileName" kind:eq value:"REGEDIT.EXE"`

Imports Registry Key From a File

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_cli

Stage 3: not filter_1

Stage 4: not filter_2

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_cli`

Stage 3: `not filter_1`

Stage 4: `not filter_2`