I'll add one more log to the mix. I'm getting the dropbox block on port 17500 but also getting blocked on port 63618 when my canon scanner software reaches out to the network to get status from my wireless printer/scanner/fax.
It looks to me like it's blocking based on an attempt by anything to broadcast to the network and not any specific application. Once I get a few minutes I'll do some more specific digging and see if I can trigger it myself and eliminate the application aspect.
-- logs --
Malwarebytes
www.malwarebytes.com
-Log Details-
Protection Event Date: 11/20/17
Protection Event Time: 2:43 PM
Log File: 0aec44f0-ce2b-11e7-9cab-305a3a589034.json
Administrator: Yes
-Software Information-
Version: 3.3.1.2183
Components Version: 1.0.236
Update Package Version: 1.0.3304
License: Premium
-System Information-
OS: Windows 10 (Build 16299.64)
CPU: x64
File System: NTFS
User: System
-Blocked Website Details-
Malicious Website: 1
, , Blocked, [-1], [-1],0.0.0
-Website Data-
Domain:
IP Address: 255.255.255.255
Port: [63618]
Type: Outbound
File: C:\Program Files (x86)\Canon\IJ Network Scanner Selector EX\CNMNSST.exe
(end)