sigmahighHunting

Suspicious Binary Writes Via AnyDesk

Detects AnyDesk writing binary files to disk other than "gcapi.dll". According to RedCanary research it is highly abnormal for AnyDesk to write executable files to disk besides gcapi.dll, which is a legitimate DLL that is part of the Google Chrome web browser used to interact with the Google Cloud API. (See reference section for more details)

MITRE ATT&CK

T1219.002

command-and-control

Detection Query

selection:
  Image|endswith:
    - \AnyDesk.exe
    - \AnyDeskMSI.exe
  TargetFilename|endswith:
    - .dll
    - .exe
filter_dlls:
  TargetFilename|endswith: \gcapi.dll
condition: selection and not 1 of filter_*

Author

Nasreddine Bencherchali (Nextron Systems)

Created

2022-09-28

Data Sources

windowsFile Events

Platforms

windows

References

Tags

attack.command-and-controlattack.t1219.002

Raw Content

title: Suspicious Binary Writes Via AnyDesk
id: 2d367498-5112-4ae5-a06a-96e7bc33a211
status: test
description: |
    Detects AnyDesk writing binary files to disk other than "gcapi.dll".
    According to RedCanary research it is highly abnormal for AnyDesk to write executable files to disk besides gcapi.dll,
    which is a legitimate DLL that is part of the Google Chrome web browser used to interact with the Google Cloud API. (See reference section for more details)
references:
    - https://redcanary.com/blog/misbehaving-rats/
    - https://thedfirreport.com/2025/02/24/confluence-exploit-leads-to-lockbit-ransomware/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-09-28
modified: 2025-02-24
tags:
    - attack.command-and-control
    - attack.t1219.002
logsource:
    product: windows
    category: file_event
detection:
    selection:
        Image|endswith:
            - '\AnyDesk.exe'
            - '\AnyDeskMSI.exe'
        TargetFilename|endswith:
            - '.dll'
            - '.exe'
    filter_dlls:
        TargetFilename|endswith: '\gcapi.dll'
    condition: selection and not 1 of filter_*
falsepositives:
    - Unknown
level: high