Detection rules › Sigma
Suspicious Schtasks Execution AppData Folder
Detects the creation of a schtask that executes a file from C:\Users<USER>\AppData\Local
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | |
| Persistence | |
| Privilege Escalation |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
| Security-Auditing | Event ID 4688: A new process has been created. |
Rule body
title: Suspicious Schtasks Execution AppData Folder
id: c5c00f49-b3f9-45a6-997e-cfdecc6e1967
status: test
description: 'Detects the creation of a schtask that executes a file from C:\Users\<USER>\AppData\Local'
references:
- https://thedfirreport.com/2022/02/21/qbot-and-zerologon-lead-to-full-domain-compromise/
author: pH-T (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2022-03-15
modified: 2022-07-28
tags:
- attack.privilege-escalation
- attack.execution
- attack.persistence
- attack.t1053.005
- attack.t1059.001
logsource:
product: windows
category: process_creation
detection:
selection:
Image|endswith: '\schtasks.exe'
CommandLine|contains|all:
- '/Create'
- '/RU'
- '/TR'
- 'C:\Users\'
- '\AppData\Local\'
CommandLine|contains:
- 'NT AUT' # This covers the usual NT AUTHORITY\SYSTEM
- ' SYSTEM ' # SYSTEM is a valid value for schtasks hence it gets it's own value with space
filter:
# FP from test set in SIGMA
ParentImage|contains|all:
- '\AppData\Local\Temp\'
- 'TeamViewer_.exe'
Image|endswith: '\schtasks.exe'
CommandLine|contains: '/TN TVInstallRestore'
condition: selection and not filter
falsepositives:
- Unknown
level: high
Stages and Predicates
Stage 0: condition
selection and not filterStage 1: selection
selection:
Image|endswith: '\schtasks.exe'
CommandLine|contains|all:
- '/Create'
- '/RU'
- '/TR'
- 'C:\Users\'
- '\AppData\Local\'
CommandLine|contains:
- 'NT AUT'
- ' SYSTEM '
Stage 2: not filter
filter:
ParentImage|contains|all:
- '\AppData\Local\Temp\'
- 'TeamViewer_.exe'
Image|endswith: '\schtasks.exe'
CommandLine|contains: '/TN TVInstallRestore'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
CommandLine | match | /TN TVInstallRestore | excludes:CommandLine field:"CommandLine" value:"/TN TVInstallRestore" |
Image | ends_with | \schtasks.exe | excludes:Image field:"Image" value:"\schtasks.exe" |
ParentImage | match | TeamViewer_.exe | excludes:ParentImage field:"ParentImage" value:"TeamViewer_.exe" |
ParentImage | match | \AppData\Local\Temp\ | excludes:ParentImage field:"ParentImage" value:"\AppData\Local\Temp\" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match |
Image | ends_with |
| field:"Image" kind:ends_with value:"\schtasks.exe" |