---
title: Startup Folder Persistence via Unsigned Process
description: Identifies files written or modified in the startup folder by unsigned processes. Adversaries may abuse this technique to maintain persistence in an environment...
url: https://www.elastic.co/docs/reference/security/prebuilt-rules/rules/windows/persistence_startup_folder_file_written_by_unsigned_process
products:
  - Elastic Security
---

# Startup Folder Persistence via Unsigned Process
Identifies files written or modified in the startup folder by unsigned processes. Adversaries may abuse this technique
to maintain persistence in an environment.
**Rule type**: eql
**Rule indices**:
- logs-endpoint.events.process-*
- logs-endpoint.events.file-*

**Rule Severity**: medium
**Risk Score**: 47
**Runs every**: 
**Searches indices from**: `now-9m`
**Maximum alerts per execution**: 100
**References**:
**Tags**:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Persistence
- Tactic: Defense Evasion
- Resources: Investigation Guide
- Data Source: Elastic Defend

**Version**: 112
**Rule authors**:
- Elastic

**Rule license**: Elastic License v2

## Investigation guide


## Triage and analysis


### Investigating Startup Folder Persistence via Unsigned Process

The Windows Startup folder is a special folder in Windows. Programs added to this folder are executed during account logon, without user interaction, providing an excellent way for attackers to maintain persistence.
This rule looks for unsigned processes writing to the Startup folder locations.> **Note**:
This investigation guide uses the [Osquery Markdown Plugin](https://www.elastic.co/guide/en/security/current/invest-guide-run-osquery.html) introduced in Elastic Stack version 8.5.0. Older Elastic Stack versions will display unrendered Markdown in this guide.

#### Possible investigation steps

- Investigate the process execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.
- Investigate other alerts associated with the user/host during the past 48 hours.
- Validate if the activity is not related to planned patches, updates, network administrator activity, or legitimate software installations.
- Assess whether this behavior is prevalent in the environment by looking for similar occurrences across hosts.
- Examine the host for derived artifacts that indicate suspicious activities:
  - Analyze the file using a private sandboxed analysis system.
- Observe and collect information about the following activities in both the sandbox and the alert subject host:
  - Attempts to contact external domains and addresses.
  - Use the Elastic Defend network events to determine domains and addresses contacted by the subject process by filtering by the process' `process.entity_id`.
- Examine the DNS cache for suspicious or anomalous entries.
  - $osquery_0
- Use the Elastic Defend registry events to examine registry keys accessed, modified, or created by the related processes in the process tree.
- Examine the host services for suspicious or anomalous entries.
  - $osquery_1
- $osquery_2
- $osquery_3
- Retrieve the files' SHA-256 hash values using the PowerShell `Get-FileHash` cmdlet and search for the existence and reputation of the hashes in resources like VirusTotal, Hybrid-Analysis, CISCO Talos, Any.run, etc.
- Investigate potentially compromised accounts. Analysts can do this by searching for login events (for example, 4624) to the target host after the registry modification.


### False positive analysis

- There is a high possibility of benign legitimate programs being added to Startup folders. This activity could be based on new software installations, patches, or any kind of network administrator related activity. Before undertaking further investigation, verify that this activity is not benign.


### Related rules

- Suspicious Startup Shell Folder Modification - c8b150f0-0164-475b-a75e-74b47800a9ff
- Persistent Scripts in the Startup Directory - f7c4dc5a-a58d-491d-9f14-9b66507121c0


### Response and remediation

- Initiate the incident response process based on the outcome of the triage.
- Isolate the involved host to prevent further post-compromise behavior.
- If the triage identified malware, search the environment for additional compromised hosts.
  - Implement temporary network rules, procedures, and segmentation to contain the malware.
- Stop suspicious processes.
- Immediately block the identified indicators of compromise (IoCs).
- Inspect the affected systems for additional malware backdoors like reverse shells, reverse proxies, or droppers that attackers could use to reinfect the system.
- Remove and block malicious artifacts identified during triage.
- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.
- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.
- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.
- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).


## Rule Query

```eql
sequence by host.id, process.entity_id with maxspan=5s
  [process where host.os.type == "windows" and event.type == "start" and process.code_signature.trusted == false and
  /* suspicious paths can be added here  */
   process.executable : ("C:\\Users\\*.exe",
                         "C:\\ProgramData\\*.exe",
                         "C:\\Windows\\Temp\\*.exe",
                         "C:\\Windows\\Tasks\\*.exe",
                         "C:\\Intel\\*.exe",
                         "C:\\PerfLogs\\*.exe")
   ]
   [file where host.os.type == "windows" and event.type != "deletion" and user.domain != "NT AUTHORITY" and
    file.path : ("C:\\Users\\*\\AppData\\Roaming\\Microsoft\\Windows\\Start Menu\\Programs\\Startup\\*",
                 "C:\\ProgramData\\Microsoft\\Windows\\Start Menu\\Programs\\StartUp\\*")
   ]
```

**Framework:** MITRE ATT&CK
- Tactic:
  - Name: Persistence
- Id: TA0003
- Reference URL: [[https://attack.mitre.org/tactics/TA0003/](https://attack.mitre.org/tactics/TA0003/)](https://attack.mitre.org/tactics/TA0003/)
- Technique:
  - Name: Boot or Logon Autostart Execution
- Id: T1547
- Reference URL: [[https://attack.mitre.org/techniques/T1547/](https://attack.mitre.org/techniques/T1547/)](https://attack.mitre.org/techniques/T1547/)
- Sub Technique:
  - Name: Registry Run Keys / Startup Folder
- Id: T1547.001
- Reference URL: [[https://attack.mitre.org/techniques/T1547/001/](https://attack.mitre.org/techniques/T1547/001/)](https://attack.mitre.org/techniques/T1547/001/)

**Framework:** MITRE ATT&CK
- Tactic:
  - Name: Defense Evasion
- Id: TA0005
- Reference URL: [[https://attack.mitre.org/tactics/TA0005/](https://attack.mitre.org/tactics/TA0005/)](https://attack.mitre.org/tactics/TA0005/)
- Technique:
  - Name: Masquerading
- Id: T1036
- Reference URL: [[https://attack.mitre.org/techniques/T1036/](https://attack.mitre.org/techniques/T1036/)](https://attack.mitre.org/techniques/T1036/)
- Sub Technique:
  - Name: Invalid Code Signature
- Id: T1036.001
- Reference URL: [[https://attack.mitre.org/techniques/T1036/001/](https://attack.mitre.org/techniques/T1036/001/)](https://attack.mitre.org/techniques/T1036/001/)