> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/analytics-alerts/alerts-by-name/an-uncommon-file-was-created-in-the-startup-folder.md).
# An uncommon file was created in the startup folder
### Synopsis
| Field | Value |
| -------------------- | --------------------------------------------------------------------------------- |
| Activation Period | 14 Days |
| Training Period | 30 Days |
| Test Period | N/A (single event) |
| Deduplication Period | 7 Days |
| Required Data | XDR Agent with eXtended Threat Hunting (XTH) |
| ATT\&CK Tactic | Persistence (TA0003) |
| ATT\&CK Technique | Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder (T1547.001) |
| Severity | Informational |
### Description
An uncommon file was created in the startup folder.
### Attacker's Goals
Maintain persistence on the host through automatic execution at startup.
### Investigative actions
* Determine if the file was created as part of a legitimate application installation, and check other files written by the same process.
* Identify which program opens this file based on its extension.
* Check the registry at HKEY\_CLASSES\_ROOT\[extension]\shell\[action]\command to see the default application or command used to execute the file.
### Variations
An executable file with a non-default extension was added to the startup folder
**Synopsis**
| Field | Value |
| ----------------- | --------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Persistence (TA0003) |
| ATT\&CK Technique | Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder (T1547.001) |
| Severity | Medium |
**Description**
An executable file with a non-default extension was added to the startup folder.
**Attacker's Goals**
Maintain persistence on the host through automatic execution at startup.
**Investigative actions**
* Determine if the file was created as part of a legitimate application installation, and check other files written by the same process.
* Identify which program opens this file based on its extension.
* Check the registry at HKEY\_CLASSES\_ROOT\[extension]\shell\[action]\command to see the default application or command used to execute the file.
An executable or script was added to the startup folder
**Synopsis**
| Field | Value |
| ----------------- | --------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Persistence (TA0003) |
| ATT\&CK Technique | Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder (T1547.001) |
| Severity | Low |
**Description**
An executable or script was added to the startup folder. This may occur during a legitimate program installation but could also indicate a malicious program persisting on the system.
**Attacker's Goals**
Maintain persistence on the host through automatic execution at startup.
**Investigative actions**
* Determine if the file was created as part of a legitimate application installation, and check other files written by the same process.
* Identify which program opens this file based on its extension.
* Check the registry at HKEY\_CLASSES\_ROOT\[extension]\shell\[action]\command to see the default application or command used to execute the file.
A file with an uncommon extension was added to the startup folder
**Synopsis**
| Field | Value |
| ----------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Persistence (TA0003) |
| ATT\&CK Technique | Event Triggered Execution: Change Default File Association (T1546.001), Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder (T1547.001) |
| Severity | Low |
**Description**
A file with an uncommon extension was added to the startup folder, which may happen on new program installation, but may also indicate a malicious program persisting itself.
**Attacker's Goals**
Persistence on the host.
**Investigative actions**
* Check if the file was set during installation process (what other files were written by the process).
* Check the registry at HKEY\_CLASSES\_ROOT.\[extension]\shell\[action]\command for the default application or command to execute.
A new shortcut (lnk) was added to the startup folder
**Synopsis**
| Field | Value |
| ----------------- | --------------------------------------------------------------------------------- |
| ATT\&CK Tactic | Persistence (TA0003) |
| ATT\&CK Technique | Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder (T1547.001) |
| Severity | Low |
**Description**
A new shortcut (lnk) file was added to the startup folder, which may happen on new program installation, but may also indicate a malicious program persisting itself.
**Attacker's Goals**
Maintain persistence on the host through automatic execution at startup.
**Investigative actions**
* Determine if the file was created as part of a legitimate application installation, and check other files written by the same process.
* Identify which program opens this file based on its extension.
* Check the registry at HKEY\_CLASSES\_ROOT\[extension]\shell\[action]\command to see the default application or command used to execute the file.
---
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