Detection rules › Splunk

Windows Powershell History File Deletion

Status
production
Severity
low
Group by
Guid, Name, Opcode, Path, ScriptBlockId, ScriptBlockText, dest, process_id, signature, signature_id, user_id, vendor_product
Author
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects the usage of PowerShell to delete its command history file, which may indicate an attempt to evade detection by removing evidence of executed commands. PowerShell stores command history in ConsoleHost_history.txt under the user’s profile directory. Adversaries or malicious scripts may delete this file using Remove-Item, del, or similar commands. This detection focuses on file deletion events targeting the history file, correlating them with recent PowerShell activity. While legitimate users may occasionally clear history, frequent or automated deletions should be investigated for potential defense evasion or post-exploitation cleanup activities.

MITRE ATT&CK coverage

Event coverage

Rule body splunk

name: Windows Powershell History File Deletion
id: f1369394-48e1-4327-bf6d-14377f4b8687
version: 7
creation_date: '2024-01-10'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects the usage of PowerShell to delete its command history file, which may indicate an attempt to evade detection by removing evidence of executed commands. PowerShell stores command history in ConsoleHost_history.txt under the user’s profile directory. Adversaries or malicious scripts may delete this file using Remove-Item, del, or similar commands. This detection focuses on file deletion events targeting the history file, correlating them with recent PowerShell activity. While legitimate users may occasionally clear history, frequent or automated deletions should be investigated for potential defense evasion or post-exploitation cleanup activities.
data_source:
    - Powershell Script Block Logging 4104
search: |-
    `powershell` EventCode=4104 ScriptBlockText = "*Remove-Item*" ScriptBlockText = "*.HistorySavePath"
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY dest signature signature_id
           user_id vendor_product Guid
           Opcode Name Path
           ProcessID ScriptBlockId ScriptBlockText
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `windows_powershell_history_file_deletion_filter`
how_to_implement: To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba.
known_false_positives: administrators may execute this command that may cause some false positive.
references:
    - https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-071a
drilldown_searches:
    - name: View the detection results for - "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: A PowerShell related to deleting commandline history file deletion was executed on $dest$.
analytic_story:
    - Medusa Ransomware
asset_type: Endpoint
mitre_attack_id:
    - T1059.003
    - T1070.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1070.003/ConsoleHost_History_deletion/HistorySavePath_powershell.log
          source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: search

`powershell` EventCode=4104 ScriptBlockText = "*Remove-Item*" ScriptBlockText = "*.HistorySavePath"

Stage 2: fillnull

| fillnull

Stage 3: stats

| stats count min(_time) as firstTime max(_time) as lastTime
    BY dest signature signature_id
       user_id vendor_product Guid
       Opcode Name Path
       ProcessID ScriptBlockId ScriptBlockText

Stage 4: search

| `security_content_ctime(firstTime)`

Stage 5: search

| `security_content_ctime(lastTime)`

Stage 6: search

| `windows_powershell_history_file_deletion_filter`

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
EventCodeeq
  • 4104 corpus 268 (splunk 268)
ScriptBlockTexteq
  • "*.HistorySavePath"
  • "*Remove-Item*" corpus 3 (sigma 2, splunk 1)