How to exclude IPs & accounts from Analytic Rule, with Watchlist?
We are trying to filter out some false positives from a Analytic rule called "Service accounts performing RemotePS". Using automation rules still gives a lot of false mail notifications we don't want so we would like to try using a watchlist with the serviceaccounts and IP combination we want to exclude. Anyone knows where and what syntax we would need to exlude the items on the specific Watchlist? Query: let InteractiveTypes = pack_array( // Declare Interactive logon type names 'Interactive', 'CachedInteractive', 'Unlock', 'RemoteInteractive', 'CachedRemoteInteractive', 'CachedUnlock' ); let WhitelistedCmdlets = pack_array( // List of whitelisted commands that don't provide a lot of value 'prompt', 'Out-Default', 'out-lineoutput', 'format-default', 'Set-StrictMode', 'TabExpansion2' ); let WhitelistedAccounts = pack_array('FakeWhitelistedAccount'); // List of accounts that are known to perform this activity in the environment and can be ignored DeviceLogonEvents // Get all logon events... | where AccountName !in~ (WhitelistedAccounts) // ...where it is not a whitelisted account... | where ActionType == "LogonSuccess" // ...and the logon was successful... | where AccountName !contains "$" // ...and not a machine logon. | where AccountName !has "winrm va_" // WinRM will have pseudo account names that match this if there is an explicit permission for an admin to run the cmdlet, so assume it is good. | extend IsInteractive=(LogonType in (InteractiveTypes)) // Determine if the logon is interactive (True=1,False=0)... | summarize HasInteractiveLogon=max(IsInteractive) // ...then bucket and get the maximum interactive value (0 or 1)... by AccountName // ... by the AccountNames | where HasInteractiveLogon == 0 // ...and filter out all accounts that had an interactive logon. // At this point, we have a list of accounts that we believe to be service accounts // Now we need to find RemotePS sessions that were spawned by those accounts // Note that we look at all powershell cmdlets executed to form a 29-day baseline to evaluate the data on today | join kind=rightsemi ( // Start by dropping the account name and only tracking the... DeviceEvents // ... | where ActionType == 'PowerShellCommand' // ...PowerShell commands seen... | where InitiatingProcessFileName =~ 'wsmprovhost.exe' // ...whose parent was wsmprovhost.exe (RemotePS Server)... | extend AccountName = InitiatingProcessAccountName // ...and add an AccountName field so the join is easier ) on AccountName // At this point, we have all of the commands that were ran by service accounts | extend Command = tostring(extractjson('$.Command', tostring(AdditionalFields))) // Extract the actual PowerShell command that was executed | where Command !in (WhitelistedCmdlets) // Remove any values that match the whitelisted cmdlets | summarize (Timestamp, ReportId)=arg_max(TimeGenerated, ReportId), // Then group all of the cmdlets and calculate the min/max times of execution... make_set(Command, 100000), count(), min(TimeGenerated) by // ...as well as creating a list of cmdlets ran and the count.. AccountName, AccountDomain, DeviceName, DeviceId // ...and have the commonality be the account, DeviceName and DeviceId // At this point, we have machine-account pairs along with the list of commands run as well as the first/last time the commands were ran | order by AccountName asc // Order the final list by AccountName just to make it easier to go through | extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName) | extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")
Incident Missing Entities
Good morning! I would like to have some clarification on how entities work. Yesterday I found out that if I have 2 entities of the same type (In this particular case, two entities of the type Account), with the same identifier (originally, both share the identifier 'Name'), Sentinel appears to throw away one of them, or both in some instances, and when the alert generates an incident, the entities defined won't appear. I have switched out the identifier on both account types to something different, but until an incident gets triggered, I can't confirm if this will fix the original issue. So my questions are An analytic rule can or can't have two entities of the same type defined? If yes, that means that they need to have different identifiers. Is this a correct asumption? Some identifiers expect a certain type of value to be assigned, that means that eventually, I can ran out of identifiers for my entities or face the added complexity of dealing with types when returning values from my KQL query What could happen if I map an identifier to something that matches the type but not what that identifier represents? in this case, for Account, we have the identifier ObjectGuid. If I assign a value type string to it, that is not a guid, wouldn't that mess up something else in the background? Example, incident grouping If I move instead to use Sentinel Entities, which appear to be the 'general' option, I could only use one, since I only have 'entity' as available identifier, looping back to the problem of can have only one type of identifier for identity type. Thanks in advance
Optimisation For Abnormal Deny Rate for Source IP
Hi, I have recently enabled the "Abnormal Deny Rate for Source IP" alert in Microsoft Sentinel and found it to be quite noisy, generating a large number of alerts many of which do not appear to be actionable. I understand that adjusting the learning period is one way to reduce this noise. However, I am wondering if there are any other optimisation strategies available that do not involve simply changing the learning window. Has anyone had success with tuning this rule using: Threshold-based suppression (e.g. minimum deny count)? Source IP allowlists? Frequency filters (e.g. repeated anomalies over multiple intervals)? Combining with other signal types before generating alerts? Open to any suggestions, experiences, or best practices that others may have found effective in reducing false positives while still maintaining visibility into meaningful anomalies. Thanks in advance,
Sentinel incident playbook - get alert entities
Hi! My main task is to get all alerts (alerts, not incidents) from sentinel (analytics rules and Defender XDR) to external case management. For different reasons we need to do this on alert level. Alert trigger by design works perfectly, but this does not trigger on Defender alerts on Sentinel, only analytic rules. When using Sentinel incident trigger, then i'm not able to extract entities related to alerts, only incident releated entities. Final output is sent with HTTP post to our external system using logic app. Any ideas how to get in logic app all alerts with their entities?
Scheduled Analytics Rule not triggering...
Hello, I am trying to trigger the following KQL query in a custom scheduled Analytics Rule... It is to identify ANY Global Administrator and verify if they have committed any activity (Sign-in) over the last 24 hours. Simple testing is to get a Global Administrator to sign in within the last 24 hours. Now the query triggers and returns records when run in the Logs pane... What I have noticed is that when activated in a custom-scheduled Analytics Rule, it fails to return records! Now the time range set for the analytics rule (query frequency & lookback duration) aligns properly with the query logic or any log ingestion delay. Query scheduling Run query every: 1 day Lookup data from the last: 1 day The funny thing is, when testing the KQL query in the Analytics Rule and Set rule logic/View query results, if the FIRST ATTEMPT returns no results (in the simulation), after repeatedly testing (clicking the test link), it DOES return records! Why is there a time-lag? How can I ensure the query triggers correctly, returning records accordingly, and related Incidents? This is the KQL query... let PrivilgedRoles = dynamic(["Global Administrator"]); let PrivilegedIdentities = IdentityInfo | summarize arg_max(TimeGenerated, *) by AccountObjectId | mv-expand AssignedRoles | where AssignedRoles in~ (PrivilgedRoles) | extend lc_AccountUPN = tolower(AccountUPN) | summarize AssignedRoles=make_set(AssignedRoles) by AccountObjectId, AccountSID, lc_AccountUPN, AccountDisplayName, JobTitle, Department; SigninLogs | where TimeGenerated > ago (1d) | extend lc_UserPrincipalName = tolower(UserPrincipalName) | join kind=inner PrivilegedIdentities on $left.lc_UserPrincipalName == $right.lc_AccountUPN | project TimeGenerated, AccountDisplayName, AccountObjectId, lc_AccountUPN, lc_UserPrincipalName, AppDisplayName, ResultType, ResultDescription, IPAddress, LocationDetails
Unknown Behaviour Involving GroupsService in OfficeActivity
I have spotted a few hundred events with the following KQL query in my environment. This is the result of one of the entries. It looks like a regular legitimate behaviour by Microsoft but I don't seem to find any documentation about it. Can anyone share the insight of it? Thank you!Add Search Results to alert details in Microsoft Sentinel
Hi everyone, I’m working with Microsoft Sentinel and looking to enhance my alerts by appending search results to the alert details. Specifically, I want to include the events that triggered these alerts in the SecurityAlert table for better context during investigations and for archival purposes. I came across this guide: https://learn.microsoft.com/en-us/azure/sentinel/customize-alert-details?tabs=azure, which explains how to customize alert details. However, it doesn’t clarify whether it’s possible to add search results directly to the alert details. Is there a way to achieve this? If so, what would be the best approach? I’d really appreciate any insights, best practices, or examples from those who have done something similar. Thanks in advance!Fetching alerts from Sentinel using logic apps
Hello everyone, I have a requirement to archive alerts from sentinel. To do that I need to do the following: Retrieve the alerts from Sentinel Send the data to an external file share As a solution, I decided to proceed with using logic apps where I will be running a script to automate this process. My questions are the following: -> Which API endpoints in sentinel are relevant to retrieve alerts or to run kql queries to get the needed data. -> I know that I will need some sort of permissions to interact with the API endpoint. What type of service account inside azure should I create and what permissions should I provision to it ? -> Is there any existing examples of logic apps interacting with ms sentinel ? That would be helpful for me as I am new to Azure. Any help is much appreciated !
