Detection rules › Sigma

Potentially Suspicious WebDAV LNK Execution

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
Micah Babinski
Source
github.com/SigmaHQ/sigma

Detects possible execution via LNK file accessed on a WebDAV server.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Potentially Suspicious WebDAV LNK Execution
id: 1412aa78-a24c-4abd-83df-767dfb2c5bbe
related:
    - id: f0507c0f-a3a2-40f5-acc6-7f543c334993
      type: similar
status: test
description: Detects possible execution via LNK file accessed on a WebDAV server.
references:
    - https://www.trellix.com/en-us/about/newsroom/stories/research/beyond-file-search-a-novel-method.html
    - https://micahbabinski.medium.com/search-ms-webdav-and-chill-99c5b23ac462
author: Micah Babinski
date: 2023-08-21
tags:
    - attack.execution
    - attack.t1059.001
    - attack.t1204
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\explorer.exe'
        Image|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\mshta.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\wscript.exe'
        CommandLine|contains: '\DavWWWRoot\'
    condition: selection
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ParentImage|endswith: '\explorer.exe'
    Image|endswith:
        - '\cmd.exe'
        - '\cscript.exe'
        - '\mshta.exe'
        - '\powershell.exe'
        - '\pwsh.exe'
        - '\wscript.exe'
    CommandLine|contains: '\DavWWWRoot\'

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
CommandLinematch
  • \DavWWWRoot\ corpus 2 (sigma 2)
Imageends_with
  • \cmd.exe corpus 130 (sigma 130)
  • \cscript.exe corpus 73 (sigma 73)
  • \mshta.exe corpus 67 (sigma 67)
  • \powershell.exe corpus 182 (sigma 182)
  • \pwsh.exe corpus 168 (sigma 168)
  • \wscript.exe corpus 75 (sigma 75)
ParentImageends_with
  • \explorer.exe corpus 13 (sigma 13)