LOLBAS Data Exfiltration by DataSvcUtil.exe — Sigma Rule

Rule metadata and linked tags

Author: Ialle Teixeira @teixeira0xfffff, Austin Songer @austinsonger. Source status: test; severity: medium. Source dates: 2021-09-30 / 2022-05-16.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: ea2e8a2517bc86b8c6720d6dec61a464e3ec69c82b35284c8664910198d8878c

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: LOLBAS Data Exfiltration by DataSvcUtil.exe
id: e290b10b-1023-4452-a4a9-eb31a9013b3a
status: test
description: Detects when a user performs data exfiltration by using DataSvcUtil.exe
references:
    - https://gist.github.com/teixeira0xfffff/837e5bfed0d1b0a29a7cb1e5dbdd9ca6
    - https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/wcf-data-service-client-utility-datasvcutil-exe
    - https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/generating-the-data-service-client-library-wcf-data-services
    - https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/how-to-add-a-data-service-reference-wcf-data-services
    - https://lolbas-project.github.io/lolbas/Binaries/DataSvcUtil/
author: Ialle Teixeira @teixeira0xfffff, Austin Songer @austinsonger
date: 2021-09-30
modified: 2022-05-16
tags:
    - attack.exfiltration
    - attack.t1567
logsource:
    category: process_creation
    product: windows
detection:
    selection_cli:
        CommandLine|contains:
            - '/in:'
            - '/out:'
            - '/uri:'
    selection_img:
        - Image|endswith: '\DataSvcUtil.exe'
        - OriginalFileName: 'DataSvcUtil.exe'
    condition: all of selection*
falsepositives:
    - DataSvcUtil.exe being used may be performed by a system administrator.
    - Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
    - DataSvcUtil.exe being executed from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.
level: medium

Original YAML and metadata in JSON

False positives

• DataSvcUtil.exe being used may be performed by a system administrator.
• Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
• DataSvcUtil.exe being executed from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

Source references

• https://gist.github.com/teixeira0xfffff/837e5bfed0d1b0a29a7cb1e5dbdd9ca6
• https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/wcf-data-service-client-utility-datasvcutil-exe
• https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/generating-the-data-service-client-library-wcf-data-services
• https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/how-to-add-a-data-service-reference-wcf-data-services
• https://lolbas-project.github.io/lolbas/Binaries/DataSvcUtil/