Detectionhightest

Suspicious Dropbox API Usage

Detects an executable that isn't dropbox but communicates with the Dropbox API

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Launch
Florian Roth (Nextron Systems)Created Wed Apr 2025eabf56-22f0-4915-a1ed-056b8dae0a68windows
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 Logic2 selectors
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith:
            - 'api.dropboxapi.com'
            - 'content.dropboxapi.com'
    filter_main_legit_dropbox:
        # Note: It's better to add a specific path to the exact location(s) where dropbox is installed
        Image|contains: '\Dropbox'
    condition: selection and not 1 of filter_main_*
False Positives

Legitimate use of the API with a tool that the author wasn't aware of

Rule Metadata
Rule ID
25eabf56-22f0-4915-a1ed-056b8dae0a68
Status
test
Level
high
Type
Detection
Created
Wed Apr 20
Path
rules/windows/network_connection/net_connection_win_domain_dropbox_api.yml
Raw Tags
attack.command-and-controlattack.exfiltrationattack.t1105attack.t1567.002
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