Device Finddeviceswithnoasr

KQL detection rule by reprise99 · MIT

Find devices in your environment that have never triggered an ASR rule, you can likely turn on ASR for these devices without causing issues for the users.

//Find devices in your environment that have never triggered an ASR rule, you can likely turn on ASR for these devices without causing issues for the users.

//Data connector required for this query - M365 Defender - Device* tables

//Microsoft Sentinel query
//First find devices that have triggered an Attack Surface Reduction rule, either block or in audit mode.
let asrdevices=
    DeviceEvents
    | where TimeGenerated > ago (30d)
    | where ActionType startswith "Asr"
    | distinct DeviceName;
//Find all devices and exclude those that have previously triggered a rule
DeviceInfo
| where TimeGenerated > ago (30d)
| where OSPlatform startswith "Windows"
| summarize arg_max(TimeGenerated, *) by DeviceName
| where DeviceName !in (asrdevices)
| project
    ['Time Last Seen']=TimeGenerated,
    DeviceId,
    DeviceName,
    OSPlatform,
    OSVersion,
    LoggedOnUsers

//Advanced Hunting query

//Data connector required for this query - Advanced Hunting license

//First find devices that have triggered an Attack Surface Reduction rule, either block or in audit mode.
let asrdevices=
    DeviceEvents
    | where Timestamp > ago (30d)
    | where ActionType startswith "Asr"
    | distinct DeviceName;
//Find all devices and exclude those that have previously triggered a rule
DeviceInfo
| where Timestamp > ago (30d)
| where OSPlatform startswith "Windows"
| summarize arg_max(Timestamp, *) by DeviceName
| where DeviceName  !in (asrdevices)
| project
    ['Time Last Seen']=Timestamp,
    DeviceId,
    DeviceName,
    OSPlatform,
    OSVersion,
    LoggedOnUsers

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

d79896e4-07a3-46ce-bc06-03176ff43406

Propose edits, view related rules, and engage with the community through comments.

Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

[[ reason ]]

What does this mean?

Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

[[ reason ]]

What do these messages mean?

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

Community Discussion