Detection rules › Splunk

Windows Scheduled Task with Suspicious Name

Status
production
Severity
medium
Group by
Command, Enabled, Hidden, computer_name, signature_id, task_name, user
Author
Steven Dick
Source
github.com/splunk/security_content

The following analytic detects the creation, modification, or enabling of scheduled tasks with known suspicious or malicious task names. It leverages Windows Security EventCode 4698, 4700, and 4702 to identify when such tasks are registered, modified, or enabled. This activity is significant as it may indicate an attempt to establish persistence or execute malicious commands on a system. If confirmed malicious, this could allow an attacker to maintain access, execute arbitrary code, or escalate privileges, posing a severe threat to the environment.

MITRE ATT&CK coverage

Event coverage

Rule body splunk

name: Windows Scheduled Task with Suspicious Name
id: 9e9ab4e3-c9d0-4967-a197-6d755e8a7e6e
version: 9
creation_date: '2025-02-07'
modification_date: '2026-05-13'
author: Steven Dick
status: production
type: TTP
description: The following analytic detects the creation, modification, or enabling of scheduled tasks with known suspicious or malicious task names. It leverages Windows Security EventCode 4698, 4700, and 4702 to identify when such tasks are registered, modified, or enabled. This activity is significant as it may indicate an attempt to establish persistence or execute malicious commands on a system. If confirmed malicious, this could allow an attacker to maintain access, execute arbitrary code, or escalate privileges, posing a severe threat to the environment.
data_source:
    - Windows Event Log Security 4698
    - Windows Event Log Security 4700
    - Windows Event Log Security 4702
search: |-
    `wineventlog_security` EventCode IN (4698,4700,4702)
    | eval TaskContent = case(isnotnull(TaskContentNew),TaskContentNew,true(),TaskContent)
    | xmlkv TaskContent
    | stats count min(_time) as firstTime max(_time) as lastTime latest(Arguments) as Arguments latest(Author) as Author by Computer, TaskName, Command, Enabled, Hidden,Caller_User_Name, EventCode
    | lookup windows_suspicious_tasks task_name as TaskName
    | where isnotnull(tool_type)
    | eval command=TaskName, process=Command+if(isnotnull(Arguments)," ".Arguments,""), src_user=Author, user = Caller_User_Name, dest = Computer
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_scheduled_task_with_suspicious_name_filter`
how_to_implement: To successfully implement this search, you need to be ingesting Windows Security Event Logs with 4698 EventCode enabled. The Windows TA is also required.
known_false_positives: False positives are possible if legitimate applications are allowed to register tasks that call a shell to be spawned. Filter as needed based on command-line or processes that are used legitimately.
references:
    - https://attack.mitre.org/techniques/T1053/005/
    - https://www.ic3.gov/CSA/2023/231213.pdf
    - https://news.sophos.com/en-us/2024/11/06/bengal-cat-lovers-in-australia-get-psspsspssd-in-google-driven-gootloader-campaign/
    - https://github.com/mthcht/awesome-lists/blob/main/Lists/suspicious_windows_tasks_list.csv
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user$"
      search: '%original_detection_search% | search dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$","$user$") | 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"
    - name: Investigate schedule tasks on $dest$
      search: '`wineventlog_security` EventCode IN (4698,4700,4702) | xmlkv TaskContent | search dest="$dest$" AND TaskName = "$TaskName$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
finding:
    title: A windows scheduled task was created with known suspicious task name [$TaskName$] on $dest$, this may be a [$tool$] indicator
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: A windows scheduled task was created with known suspicious task name [$TaskName$] on $dest$, this may be a [$tool$] indicator
threat_objects:
    - field: Command
      type: signature
analytic_story:
    - Scheduled Tasks
    - Windows Persistence Techniques
    - Ransomware
    - Ryuk Ransomware
    - 0bj3ctivity Stealer
    - APT37 Rustonotto and FadeStealer
    - Castle RAT
asset_type: Endpoint
mitre_attack_id:
    - T1053.005
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/T1053.005/winevent_scheduled_task_with_suspect_name/windows-xml.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: search

`wineventlog_security` EventCode IN (4698,4700,4702)

Stage 2: eval

| eval TaskContent = case(isnotnull(TaskContentNew),TaskContentNew,true(),TaskContent)
TaskContent =
ifisnotnull(TaskContentNew)TaskContentNew
elseTaskContent

Stage 3: xmlkv

| xmlkv TaskContent

Stage 4: stats

| stats count min(_time) as firstTime max(_time) as lastTime latest(Arguments) as Arguments latest(Author) as Author by Computer, TaskName, Command, Enabled, Hidden,Caller_User_Name, EventCode

Stage 5: lookup

| lookup windows_suspicious_tasks task_name as TaskName
Lookup table
windows_suspicious_tasks
Key field
task_name as TaskName

Stage 6: where

| where isnotnull(tool_type)

Stage 7: eval

| eval command=TaskName, process=Command+if(isnotnull(Arguments)," ".Arguments,""), src_user=Author, user = Caller_User_Name, dest = Computer

Stage 8: search

| `security_content_ctime(firstTime)`

Stage 9: search

| `security_content_ctime(lastTime)`

Stage 10: search

| `windows_scheduled_task_with_suspicious_name_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
EventCodein
  • 4698 corpus 14 (splunk 14)
  • 4700
  • 4702
tool_typeis_not_null
  • (no value, null check)