Windows Private Keys Discovery
SPLUNK detection rule by Teoderick Contreras, Splunk · Apache-2.0
The following analytic identifies processes that retrieve information related to private key files, often used by post-exploitation tools like winpeas.
This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that search for private key certificates.
This activity is significant as it indicates potential attempts to locate insecurely stored credentials, which adversaries can exploit for privilege escalation, persistence, or remote service authentication.
If confirmed malicious, this behavior could allow attackers to access sensitive information, escalate privileges, or maintain persistence within the compromised environment.
name: Windows Private Keys Discovery
id: 5c1c2877-06c0-40ee-a1a2-db71f1372b5b
version: 13
creation_date: '2022-12-06'
modification_date: '2026-08-31'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: |-
The following analytic identifies processes that retrieve information related to private key files, often used by post-exploitation tools like winpeas.
This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that search for private key certificates.
This activity is significant as it indicates potential attempts to locate insecurely stored credentials, which adversaries can exploit for privilege escalation, persistence, or remote service authentication.
If confirmed malicious, this behavior could allow attackers to access sensitive information, escalate privileges, or maintain persistence within the compromised environment.
data_source:
- Sysmon EventID 1
- Windows Event Log Security 4688
- CrowdStrike ProcessRollup2
search: |-
| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
FROM datamodel=Endpoint.Processes WHERE
Processes.process_name IN (
"cmd.exe",
"findstr.exe",
"powershell.exe",
"pwsh.exe"
)
Processes.process IN (
"*.asc*",
"*.cer*",
"*.csr*",
"*.der*",
"*.gpg*",
"*.key*",
"*.ovpn*",
"*.p12*",
"*.p12*",
"*.p7b*",
"*.pem*",
"*.pfx*",
"*.pgp*",
"*.ppk*",
"*.rdg*"
)
BY Processes.action Processes.dest Processes.original_file_name
Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
Processes.process Processes.process_exec Processes.process_guid
Processes.process_hash Processes.process_id Processes.process_integrity_level
Processes.process_name Processes.process_path Processes.user
Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| regex process="(?i)[^\.\-\_\$a-zA-Z](dir\s|findstr)"
| regex process="(?i)\.(?:rdg|gpg|pgp|p12|der|csr|cer|ovpn|key|ppk|p12|pem|pfx|p7b|asc)\b"
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_private_keys_discovery_filter`
how_to_implement: |-
The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: |-
Very long command line arguments may contain these keywords in irrelevant sections of the code.
references:
- https://attack.mitre.org/techniques/T1552/004/
- https://github.com/carlospolop/PEASS-ng/tree/master/winPEAS
- https://www.microsoft.com/en-us/security/blog/2022/10/14/new-prestige-ransomware-impacts-organizations-in-ukraine-and-poland/
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 process with commandline [$process$] that can retrieve information related to private keys was executed on [$dest$]
threat_objects:
- field: parent_process
type: process
- field: process
type: process
analytic_story:
- Windows Post-Exploitation
- Prestige Ransomware
asset_type: Endpoint
mitre_attack_id:
- T1552.004
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/malware/winpeas/winpeas_search_private_key/dir-private-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
CIRCL