Detection rules › Sigma

Suspicious Deno File Written from Remote Source

Status
experimental
Severity
low
Log source
category file_event, product windows
Author
Josh Nickels, Michael Taggart
Source
github.com/SigmaHQ/sigma

Detects Deno writing a file from a direct HTTP(s) call and writing to the appdata folder or bringing it's own malicious DLL. This behavior may indicate an attempt to execute remotely hosted, potentially malicious files through deno.

Known false positives

  • Legitimate usage of deno to request a file or bring a DLL to a host

MITRE ATT&CK coverage

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 11: FileCreate

Rule body

title: Suspicious Deno File Written from Remote Source
id: 6c0ce3b6-85e2-49d4-9c3f-6e008ce9796e
status: experimental
description: |
    Detects Deno writing a file from a direct HTTP(s) call and writing to the appdata folder or bringing it's own malicious DLL.
    This behavior may indicate an attempt to execute remotely hosted, potentially malicious files through deno.
references:
    - https://taggart-tech.com/evildeno/
author: Josh Nickels, Michael Taggart
date: 2025-05-22
tags:
    - attack.execution
    - attack.t1204
    - attack.t1059.007
    - attack.command-and-control
    - attack.t1105
logsource:
    category: file_event
    product: windows
detection:
    selection_path:
        TargetFilename|contains:
            - '\deno\gen\'
            - '\deno\remote\https\'
        TargetFilename|contains|all:
            - ':\Users\'
            - '\AppData\'
    condition: selection_path
falsepositives:
    - Legitimate usage of deno to request a file or bring a DLL to a host
level: low

Stages and Predicates

Stage 0: condition

selection_path

Stage 1: selection_path

selection_path:
    TargetFilename|contains:
        - '\deno\gen\'
        - '\deno\remote\https\'
    TargetFilename|contains|all:
        - ':\Users\'
        - '\AppData\'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
TargetFilenamematch
  • :\Users\ corpus 4 (sigma 4)
  • \AppData\ corpus 4 (sigma 4)
  • \deno\gen\
  • \deno\remote\https\
field:"TargetFilename" kind:match