Custom Detection Rule For CUPS Installation In Defender XDR
Query
// Custom Detection Rule for CUPS Installation in DefenderXDR
// I’ve come up with an exciting idea! 😅 How about a custom detection rule in DefenderXDR that identifies CUPS installations and automatically isolates the device if it detects an inbound UDP packet on port 631? This could serve as an auto-defense mechanism. What do you think—could it work? 🤔
// Custom DefenderXDR Rule for CUPS Installation Detection and Isolation
let EndpointwithCUPS =
DeviceTvmSoftwareInventory
| where SoftwareName has "cups"
| project DeviceName;
DeviceNetworkEvents
| where DeviceName has_any(EndpointwithCUPS)
| where Protocol has "Udp"
| where LocalPort in (631)
| where ActionType == "InboundConnectionAttempt"
or ActionType == "ConnectionFailed"
//Explanation
This query is designed to create a custom detection rule in DefenderXDR to identify and respond to CUPS (Common UNIX Printing System) installations. Here's a simple summary:
-
Identify Devices with CUPS Installed:
- The query first searches for devices that have CUPS software installed by looking through the software inventory.
-
Monitor Network Events on These Devices:
- It then monitors network events on these identified devices, specifically looking for inbound UDP packets on port 631 (which is used by CUPS).
-
Trigger Actions Based on Network Events:
- If an inbound connection attempt or connection failure is detected on port 631, the rule can trigger an automatic response, such as isolating the device to protect the network.
In essence, this rule aims to automatically detect and respond to potential threats related to CUPS installations by monitoring specific network activities and taking defensive actions.
Details

Steven Lim
Released: September 27, 2024
Tables
DeviceTvmSoftwareInventoryDeviceNetworkEvents
Keywords
Devices
Operators
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