SecurityEvent - Multiple authentication failures followed by a success

Requête originale, sans modification.

let timeRange = 2h;
let authenticationWindow = 1h;
let authenticationThreshold = 5;
SecurityEvent
| where TimeGenerated > ago(timeRange)
| where EventID in (4624, 4625)
| where IpAddress != "-" and isnotempty(Account)
| extend Outcome = iff(EventID == 4624, "Success", "Failure")
// bin outcomes into 10 minute windows to reduce the volume of data
| summarize OutcomeCount=count() by bin(TimeGenerated, 10m), Account, IpAddress, Computer, Outcome
| project TimeGenerated, Account, IpAddress, Computer, Outcome, OutcomeCount
// sort ready for sessionizing - by account and time of the authentication outcome
| sort by TimeGenerated asc, Account, IpAddress, Computer, Outcome, OutcomeCount
| serialize
// sessionize into failure groupings until either the account changes or there is a success
| extend SessionStartedUtc = row_window_session(TimeGenerated, timeRange, authenticationWindow, Account != prev(Account) or prev(Outcome) == "Success")
// count the failures in each session
| summarize FailureCountBeforeSuccess=sumif(OutcomeCount, Outcome == "Failure"), StartTime=min(TimeGenerated), EndTime=max(TimeGenerated), make_list(Outcome, 128), make_set(Computer, 128), make_set(IpAddress, 128) by SessionStartedUtc, Account
// the session must not start with a success, and must end with one
| where array_index_of(list_Outcome, "Success") != 0
| where array_index_of(list_Outcome, "Success") == array_length(list_Outcome) - 1
| project-away SessionStartedUtc, list_Outcome
// where the number of failures before the success is above the threshold
| where FailureCountBeforeSuccess >= authenticationThreshold
// expand out ip and computer for customer entity assignment
| mv-expand set_IpAddress, set_Computer
| extend IpAddress = tostring(set_IpAddress), Computer = tostring(set_Computer)
| extend timestamp=StartTime, NTDomain = split(Account, '\\', 0)[0], Name = split(Account, '\\', 1)[0], HostName = tostring(split(Computer, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(Computer, '.'), 1, -1), '.'))