name: PowerShell Start-BitsTransfer
id: 39e2605a-90d8-11eb-899e-acde48001122
version: 2
date: '2021-03-29'
author: Michael Haag, Splunk
status: production
type: TTP
description: Start-BitsTransfer is the PowerShell "version" of BitsAdmin.exe. Similar
  functionality is present. This technique variation is not as commonly used by adversaries,
  but has been abused in the past. Lesser known uses include the ability to set the
  `-TransferType` to `Upload` for exfiltration of files. In an instance where `Upload`
  is used, it is highly possible files will be archived. During triage, review parallel
  processes and process lineage. Capture any files on disk and review. For the remote
  domain or IP, what is the reputation?
data_source:
- Sysmon Event ID 1
search:
  selection1:
    OriginalFileName: pwsh.dll
  selection2:
    Image|endswith:
    - pwsh.exe
    - sqlps.exe
    - sqltoolsps.exe
    - powershell.exe
    - powershell_ise.exe
  selection3:
    OriginalFileName: PowerShell.EXE
  selection4:
    OriginalFileName: powershell_ise.EXE
  selection5:
    CommandLine: '*start-bitstransfer*'
  condition: (selection1 or selection2 or selection3 or selection4) and selection5
how_to_implement: To successfully implement this search you need to be ingesting information
  on process that include the name of the process responsible for the changes from
  your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition,
  confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
  endpoint product.
known_false_positives: Limited false positives. It is possible administrators will
  utilize Start-BitsTransfer for administrative tasks, otherwise filter based parent
  process or command-line arguments.
references:
- https://isc.sans.edu/diary/Investigating+Microsoft+BITS+Activity/23281
- https://docs.microsoft.com/en-us/windows/win32/bits/using-windows-powershell-to-create-bits-transfer-jobs
tags:
  analytic_story:
  - BITS Jobs
  asset_type: Endpoint
  confidence: 80
  impact: 70
  message: A suspicious process $process_name$ with commandline $process$ that are
    related to bittransfer functionality in host $dest$
  mitre_attack_id:
  - T1197
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: user
    type: User
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 56
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1197/atomic_red_team/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog