Tap Installer Execution

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Daniil Yugoslavskiy, Ian Davis, oscd.community
Source: github.com/SigmaHQ/sigma

Well-known TAP software installation. Possible preparation for data exfiltration using tunneling techniques

Known false positives

Legitimate OpenVPN TAP installation

MITRE ATT&CK coverage

Tactic	Techniques
Exfiltration	`T1048` Exfiltration Over Alternative Protocol

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: Tap Installer Execution
id: 99793437-3e16-439b-be0f-078782cf953d
status: test
description: Well-known TAP software installation. Possible preparation for data exfiltration using tunneling techniques
references:
    - https://community.openvpn.net/openvpn/wiki/ManagingWindowsTAPDrivers
author: Daniil Yugoslavskiy, Ian Davis, oscd.community
date: 2019-10-24
modified: 2023-12-11
tags:
    - attack.exfiltration
    - attack.t1048
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\tapinstall.exe'
    filter_optional_avast:
        Image|contains:
            - ':\Program Files\Avast Software\SecureLine VPN\'
            - ':\Program Files (x86)\Avast Software\SecureLine VPN\'
    filter_optional_openvpn:
        Image|contains: ':\Program Files\OpenVPN Connect\drivers\tap\'
    filter_optional_protonvpn:
        Image|contains: ':\Program Files (x86)\Proton Technologies\ProtonVPNTap\installer\'
    condition: selection and not 1 of filter_optional_*
falsepositives:
    - Legitimate OpenVPN TAP installation
level: medium

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_optional_*

Stage 1: `selection`

selection:
    Image|endswith: '\tapinstall.exe'

Stage 2: `not filter_optional_*`

filter_optional_avast:
    Image|contains:
        - ':\Program Files\Avast Software\SecureLine VPN\'
        - ':\Program Files (x86)\Avast Software\SecureLine VPN\'
filter_optional_openvpn:
    Image|contains: ':\Program Files\OpenVPN Connect\drivers\tap\'
filter_optional_protonvpn:
    Image|contains: ':\Program Files (x86)\Proton Technologies\ProtonVPNTap\installer\'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`Image`	match	`:\Program Files (x86)\Avast Software\SecureLine VPN\`	`excludes:Image` `field:"Image" value:":\Program Files (x86)\Avast Software\SecureLine VPN\"`
`Image`	match	`:\Program Files (x86)\Proton Technologies\ProtonVPNTap\installer\`	`excludes:Image` `field:"Image" value:":\Program Files (x86)\Proton Technologies\ProtonVPNTap\installer\"`
`Image`	match	`:\Program Files\Avast Software\SecureLine VPN\`	`excludes:Image` `field:"Image" value:":\Program Files\Avast Software\SecureLine VPN\"`
`Image`	match	`:\Program Files\OpenVPN Connect\drivers\tap\`	`excludes:Image` `field:"Image" value:":\Program Files\OpenVPN Connect\drivers\tap\"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`\tapinstall.exe`	`field:"Image" kind:ends_with value:"\tapinstall.exe"`