Detection rules › Sigma

Network Connection Initiated To BTunnels Domains

Status
test
Severity
medium
Log source
product windows, category network_connection
Author
Kamran Saifullah
Source
github.com/SigmaHQ/sigma

Detects network connections to BTunnels domains initiated by a process on the system. Attackers can abuse that feature to establish a reverse shell or persistence on a machine.

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1572 Protocol Tunneling
ExfiltrationT1567 Exfiltration Over Web Service

Event coverage

ProviderEventTitle
SysmonEvent ID 3Network connection

Rule body yaml

title: Network Connection Initiated To BTunnels Domains
id: 9e02c8ec-02b9-43e8-81eb-34a475ba7965
status: test
description: |
    Detects network connections to BTunnels domains initiated by a process on the system.
    Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
references:
    - https://defr0ggy.github.io/research/Utilizing-BTunnel-For-Data-Exfiltration/
author: Kamran Saifullah
date: 2024-09-13
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567
    - attack.t1572
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith: '.btunnel.co.in'
    condition: selection
falsepositives:
    - Legitimate use of BTunnels will also trigger this.
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Initiated: 'true'
    DestinationHostname|endswith: '.btunnel.co.in'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
DestinationHostnameends_with
  • .btunnel.co.in
Initiatedeq
  • true corpus 50 (sigma 50)