Add Potential Suspicious New Download Source To Winget

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects usage of winget to add new potentially suspicious download sources

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059` Command and Scripting Interpreter

Telemetry coverage

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

Rule body

title: Add Potential Suspicious New Download Source To Winget
id: c15a46a0-07d4-4c87-b4b6-89207835a83b
related:
    - id: 05ebafc8-7aa2-4bcd-a269-2aec93f9e842
      type: similar
    - id: 81a0ecb5-0a41-4ba1-b2ba-c944eb92bfa2
      type: similar
status: test
description: Detects usage of winget to add new potentially suspicious download sources
references:
    - https://learn.microsoft.com/en-us/windows/package-manager/winget/source
    - https://github.com/nasbench/Misc-Research/tree/b9596e8109dcdb16ec353f316678927e507a5b8d/LOLBINs/Winget
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-04-17
modified: 2023-12-04
tags:
    - attack.execution
    - attack.t1059
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\winget.exe'
        - OriginalFileName: 'winget.exe'
    selection_cli:
        CommandLine|contains|all:
            - 'source '
            - 'add '
    selection_source_direct_ip:
        # This is a best effort. A better way to handle this is to limit it via whitelist. Check Group Policy for more details
        CommandLine|re: '://\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_img`

selection_img:
    - Image|endswith: '\winget.exe'
    - OriginalFileName: 'winget.exe'

Stage 2: `selection_cli`

selection_cli:
    CommandLine|contains|all:
        - 'source '
        - 'add '

Stage 3: `selection_source_direct_ip`

selection_source_direct_ip:
    CommandLine|re: '://\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`add` corpus 12 (sigma 12) `source` corpus 3 (sigma 3)	`field:"CommandLine" kind:match`
`CommandLine`	regex_match	`://\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}` corpus 2 (sigma 2)	`field:"CommandLine" kind:regex_match value:"://\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}"`
`Image`	ends_with	`\winget.exe` corpus 5 (sigma 5)	`field:"Image" kind:ends_with value:"\winget.exe"`
`OriginalFileName`	eq	`winget.exe` corpus 4 (sigma 4)	`field:"OriginalFileName" kind:eq value:"winget.exe"`

Add Potential Suspicious New Download Source To Winget

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_cli

Stage 3: selection_source_direct_ip

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_cli`

Stage 3: `selection_source_direct_ip`