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Outbound Network Connection Initiated By Microsoft Dialer

Detects outbound network connection initiated by Microsoft Dialer. The Microsoft Dialer, also known as Phone Dialer, is a built-in utility application included in various versions of the Microsoft Windows operating system. Its primary function is to provide users with a graphical interface for managing phone calls via a modem or a phone line connected to the computer. This is an outdated process in the current conext of it's usage and is a common target for info stealers for process injection, and is used to make C2 connections, common example is "Rhadamanthys"

MITRE ATT&CK

T1071.001

executioncommand-and-control

Detection Query

selection:
  Image|endswith: :\Windows\System32\dialer.exe
  Initiated: "true"
filter_main_local_ranges:
  DestinationIp|cidr:
    - 127.0.0.0/8
    - 10.0.0.0/8
    - 172.16.0.0/12
    - 192.168.0.0/16
    - 169.254.0.0/16
    - ::1/128
    - fe80::/10
    - fc00::/7
condition: selection and not 1 of filter_main_*

Author

CertainlyP

Created

2024-04-26

Data Sources

windowsNetwork Connection Events

Platforms

windows

References

Tags

attack.executionattack.command-and-controlattack.t1071.001

Raw Content

title: Outbound Network Connection Initiated By Microsoft Dialer
id: 37e4024a-6c80-4d8f-b95d-2e7e94f3a8d1
status: test
description: |
    Detects outbound network connection initiated by Microsoft Dialer.
    The Microsoft Dialer, also known as Phone Dialer, is a built-in utility application included in various versions of the Microsoft Windows operating system. Its primary function is to provide users with a graphical interface for managing phone calls via a modem or a phone line connected to the computer.
    This is an outdated process in the current conext of it's usage and is a common target for info stealers for process injection, and is used to make C2 connections, common example is "Rhadamanthys"
references:
    - https://tria.ge/240301-rk34sagf5x/behavioral2
    - https://app.any.run/tasks/6720b85b-9c53-4a12-b1dc-73052a78477d
    - https://research.checkpoint.com/2023/rhadamanthys-v0-5-0-a-deep-dive-into-the-stealers-components/
    - https://strontic.github.io/xcyclopedia/library/dialer.exe-0B69655F912619756C704A0BF716B61F.html
author: CertainlyP
date: 2024-04-26
tags:
    - attack.execution
    - attack.command-and-control
    - attack.t1071.001
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Image|endswith: ':\Windows\System32\dialer.exe'
        Initiated: 'true'
    filter_main_local_ranges:
        DestinationIp|cidr:
            - '127.0.0.0/8'
            - '10.0.0.0/8'
            - '172.16.0.0/12'
            - '192.168.0.0/16'
            - '169.254.0.0/16'
            - '::1/128'  # IPv6 loopback
            - 'fe80::/10'  # IPv6 link-local addresses
            - 'fc00::/7'  # IPv6 private addresses
    condition: selection and not 1 of filter_main_*
falsepositives:
    - In Modern Windows systems, unable to see legitimate usage of this process, However, if an organization has legitimate purpose for this there can be false positives.
level: high