Device Interesting Ports Opened
Query
//Use the DeviceNetworkEvents to find what listening ports are being opened on a device and then query that list
//You can look for SSH, DNS etc being run from your end user devices
//Data connector required for this query - M365 Defender - Device* tables
//Microsoft Sentinel query
DeviceNetworkEvents
| where TimeGenerated > ago(7d)
| where ActionType == "ListeningConnectionCreated"
//Exclude high ports
| where LocalPort < 1025
| summarize ['Ports Opened']=make_set(LocalPort), ['Count of Ports Opened']=dcount(LocalPort) by DeviceName
//Look for machines running services such as FTP, SSH, DNS etc
| where ['Ports Opened'] has_any ("21","22","53")
//Advanced Hunting query
//Data connector required for this query - Advanced Hunting license
DeviceNetworkEvents
| where Timestamp > ago(7d)
| where ActionType == "ListeningConnectionCreated"
//Exclude high ports
| where LocalPort < 1025
| summarize ['Ports Opened']=make_set(LocalPort), ['Count of Ports Opened']=dcount(LocalPort) by DeviceName
//Look for machines running services such as FTP, SSH, DNS etc
| where ['Ports Opened'] has_any ("21","22","53")Explanation
This query is used to find the listening ports that are being opened on a device. It looks for ports such as SSH, DNS, FTP, etc. The query filters the DeviceNetworkEvents table and excludes high ports. It then summarizes the opened ports and counts them for each device. Finally, it filters the results to only include devices that have opened ports for services like FTP, SSH, DNS, etc.
Details
Matt Zorich
Released: June 17, 2022
Tables
DeviceNetworkEvents
Keywords
DeviceNetworkEventsTimeGeneratedActionTypeListeningConnectionCreatedLocalPortDeviceNamePorts OpenedCount of Ports OpenedTimestamp
Operators
|where>ago==make_setdcountbyhas_any