Detection rules › Splunk

Windows Modify Registry ProxyEnable

Status
production
Severity
low
Group by
TargetObject, computer_name, details, event_type, process_guid, process_id, registry_hive, registry_path, registry_status, registry_value_name, registry_value_type, user, vendor_product
Author
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects modifications to the Windows registry key "ProxyEnable" to enable proxy settings. It leverages data from the Endpoint.Registry datamodel, specifically monitoring changes to the "Internet Settings\ProxyEnable" registry path. This activity is significant as it is commonly exploited by malware and adversaries to establish proxy communication, potentially connecting to malicious Command and Control (C2) servers. If confirmed malicious, this could allow attackers to redirect network traffic through a proxy, facilitating unauthorized communication and data exfiltration, thereby compromising the security of the affected host.

Known false positives

  • Administrators may enable or disable this feature that may cause some false positive, however is not common. Filter as needed.

MITRE ATT&CK coverage

TacticTechniques
Persistence
Defense Impairment

Telemetry coverage

Rule body

name: Windows Modify Registry ProxyEnable
id: b27f20bd-ef20-41d1-a1e9-25dedd5bf2f5
version: 11
creation_date: '2023-12-06'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects modifications to the Windows registry key "ProxyEnable" to enable proxy settings. It leverages data from the Endpoint.Registry datamodel, specifically monitoring changes to the "Internet Settings\ProxyEnable" registry path. This activity is significant as it is commonly exploited by malware and adversaries to establish proxy communication, potentially connecting to malicious Command and Control (C2) servers. If confirmed malicious, this could allow attackers to redirect network traffic through a proxy, facilitating unauthorized communication and data exfiltration, thereby compromising the security of the affected host.
data_source:
    - Sysmon EventID 13
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where Registry.registry_path = "*\\Internet Settings\\ProxyEnable"  Registry.registry_value_data = 0x00000001 by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_modify_registry_proxyenable_filter`'
how_to_implement: To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the `Endpoint` datamodel in the `Registry` node. Also make sure that this registry was included in your config files ex. sysmon config to be monitored.
known_false_positives: Administrators may enable or disable this feature that may cause some false positive, however is not common. Filter as needed.
references:
    - https://malpedia.caad.fkie.fraunhofer.de/details/win.darkgate
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: the registry settings was modified to enable proxy on $dest$.
analytic_story:
    - DarkGate Malware
asset_type: Endpoint
mitre_attack_id:
    - T1112
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where Registry.registry_path = "*\\Internet Settings\\ProxyEnable"  Registry.registry_value_data = 0x00000001 by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product

Stage 2: search

| `drop_dm_object_name(Registry)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_modify_registry_proxyenable_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Registry.registry_patheq
  • "*\\Internet Settings\\ProxyEnable"
field:"registry_path" kind:eq
Registry.registry_value_dataeq
  • 0x00000001 corpus 61 (splunk 52, elastic 9)
field:"Details" kind:eq value:"0x00000001"