Detectionlowtest

Potentially Suspicious Network Connection To Notion API

Detects a non-browser process communicating with the Notion API. This could indicate potential use of a covert C2 channel such as "OffensiveNotion C2"

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Gavin KnappCreated Wed May 037e9cf7b6-e827-11ed-a05b-15959c120003windows

Log Source

WindowsNetwork Connection

ProductWindows← raw: windows

CategoryNetwork Connection← raw: network_connection

Events for outbound and inbound network connections including DNS resolution.

Detection Logic

detection:
    selection:
        DestinationHostname|contains: 'api.notion.com'
    filter_main_notion:
        Image|endswith: '\AppData\Local\Programs\Notion\Notion.exe'
    filter_main_brave:
        Image|endswith: '\brave.exe'
    filter_main_chrome:
        Image:
            - 'C:\Program Files\Google\Chrome\Application\chrome.exe'
            - 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe'
    filter_main_firefox:
        Image:
            - 'C:\Program Files\Mozilla Firefox\firefox.exe'
            - 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'
    filter_main_ie:
        Image:
            - 'C:\Program Files (x86)\Internet Explorer\iexplore.exe'
            - 'C:\Program Files\Internet Explorer\iexplore.exe'
    filter_main_maxthon:
        Image|endswith: '\maxthon.exe'
    filter_main_edge_1:
        - Image|startswith: 'C:\Program Files (x86)\Microsoft\EdgeWebView\Application\'
        - Image|endswith: '\WindowsApps\MicrosoftEdge.exe'
        - Image:
              - 'C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe'
              - 'C:\Program Files\Microsoft\Edge\Application\msedge.exe'
    filter_main_edge_2:
        Image|startswith:
            - 'C:\Program Files (x86)\Microsoft\EdgeCore\'
            - 'C:\Program Files\Microsoft\EdgeCore\'
        Image|endswith:
            - '\msedge.exe'
            - '\msedgewebview2.exe'
    filter_main_opera:
        Image|endswith: '\opera.exe'
    filter_main_safari:
        Image|endswith: '\safari.exe'
    filter_main_seamonkey:
        Image|endswith: '\seamonkey.exe'
    filter_main_vivaldi:
        Image|endswith: '\vivaldi.exe'
    filter_main_whale:
        Image|endswith: '\whale.exe'
    condition: selection and not 1 of filter_main_*

False Positives

Legitimate applications communicating with the "api.notion.com" endpoint that are not already in the exclusion list. The desktop and browser applications do not appear to be using the API by default unless integrations are configured.

References

MITRE ATT&CK

Tactics

TA0011 · Command and Control

Techniques

T1102 · Web Service

Rule Metadata

Rule ID