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Set event.outcome based on raw keyword value (#20564) (#20611)
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Set the event.outcome value if the event contains the "audit failure" or "audit success" keywords.
The `Keywords` value in the XML is a hex value where each bit can represent a keyword. So this
checks if the audit success or audit failure bits are set then adds `event.outcome` as either
"success" or "failure".

I removed similar logic from the Security module since it is now redundant. That logic was based
on string matching of the keyword name (rather than number) so it had problems when the OS
language was not English.

Fixes #20079

(cherry picked from commit 16ea8e2)
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andrewkroh authored Aug 24, 2020
1 parent 96b5843 commit c1c966e
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Showing 5 changed files with 17 additions and 44 deletions.
1 change: 1 addition & 0 deletions CHANGELOG.next.asciidoc
Original file line number Diff line number Diff line change
Expand Up @@ -377,6 +377,7 @@ field. You can revert this change by configuring tags for the module and omittin
*Winlogbeat*

- Fix invalid IP addresses in DNS query results from Sysmon data. {issue}18432[18432] {pull}18436[18436]
- Fix `event.outcome` in the security module for non-English languages. {issue}20079[20079] {pull}20564[2056
- Fix duplicated field error when exporting index-pattern with migration.6_to_7.enabled. {issue}20521[20521] {pull}20540[20540]

*Functionbeat*
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12 changes: 12 additions & 0 deletions winlogbeat/eventlog/eventlog.go
Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,12 @@ var (
readErrors = expvar.NewMap("read_errors")
)

// Keyword Constants
const (
keywordAuditFailure = 0x10000000000000
keywordAuditSuccess = 0x20000000000000
)

// EventLog is an interface to a Windows Event Log.
type EventLog interface {
// Open the event log. state points to the last successfully read event
Expand Down Expand Up @@ -138,6 +144,12 @@ func (e Record) ToEvent() beat.Event {

m.Put("event.created", time.Now())

if e.KeywordsRaw&keywordAuditFailure > 0 {
m.Put("event.outcome", "failure")
} else if e.KeywordsRaw&keywordAuditSuccess > 0 {
m.Put("event.outcome", "success")
}

addOptional(m, "log.file.path", e.File)
addOptional(m, "log.level", strings.ToLower(e.Level))
addOptional(m, "message", sys.RemoveWindowsLineEndings(e.Message))
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4 changes: 2 additions & 2 deletions winlogbeat/sys/event.go
Original file line number Diff line number Diff line change
Expand Up @@ -235,10 +235,10 @@ func (v *HexInt64) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
return err
}

num, err := strconv.ParseInt(s, 0, 64)
num, err := strconv.ParseUint(s, 0, 64)
if err != nil {
// Ignore invalid version values.
return nil
return err
}

*v = HexInt64(num)
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4 changes: 2 additions & 2 deletions winlogbeat/sys/event_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,7 @@ const allXML = `
<Level>4</Level>
<Task>9</Task>
<Opcode>0</Opcode>
<Keywords>0x4000000000000004</Keywords>
<Keywords>0x8020000000000000</Keywords>
<TimeCreated SystemTime="2016-01-28T20:33:27.990735300Z"/>
<EventRecordID>100</EventRecordID>
<Correlation ActivityID="{A066CCF1-8AB3-459B-B62F-F79F957A5036}" RelatedActivityID="{85FC0930-9C49-42DA-804B-A7368104BD1B}" />
Expand Down Expand Up @@ -94,7 +94,7 @@ func TestXML(t *testing.T) {
EventIdentifier: EventIdentifier{ID: 91},
LevelRaw: 4,
TaskRaw: 9,
KeywordsRaw: 0x4000000000000004,
KeywordsRaw: 0x8020000000000000,
TimeCreated: TimeCreated{allXMLTimeCreated},
RecordID: 100,
Correlation: Correlation{"{A066CCF1-8AB3-459B-B62F-F79F957A5036}", "{85FC0930-9C49-42DA-804B-A7368104BD1B}"},
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40 changes: 0 additions & 40 deletions x-pack/winlogbeat/module/security/config/winlogbeat-security.js
Original file line number Diff line number Diff line change
Expand Up @@ -21,13 +21,6 @@ var security = (function () {
"11": "CachedInteractive",
};

// ECS Allowed Event Outcome
// https://www.elastic.co/guide/en/ecs/current/ecs-allowed-values-event-outcome.html
var eventOutcomes = {
"Audit Success": "success",
"Audit Failure": "failure",
};

// User Account Control Attributes Table
// https://support.microsoft.com/es-us/help/305144/how-to-use-useraccountcontrol-to-manipulate-user-account-properties
var uacFlags = [
Expand Down Expand Up @@ -1361,18 +1354,6 @@ var security = (function () {
}
};

var addEventOutcome = function(evt) {
var auditResult = evt.Get("winlog.keywords");
if (!auditResult) {
return;
}
var eventOutcome = eventOutcomes[auditResult];
if (eventOutcome === undefined) {
return;
}
evt.Put("event.outcome", eventOutcome);
};

var addLogonType = function(evt) {
var code = evt.Get("winlog.event_data.LogonType");
if (!code) {
Expand Down Expand Up @@ -1699,7 +1680,6 @@ var security = (function () {
.Add(copyTargetUserLogonId)
.Add(addLogonType)
.Add(addEventFields)
.Add(addEventOutcome)
.Build();

// Handles both 4624
Expand All @@ -1709,7 +1689,6 @@ var security = (function () {
.Add(addLogonType)
.Add(renameCommonAuthFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
var user = evt.Get("winlog.event_data.SubjectUserName");
if (user) {
Expand All @@ -1727,7 +1706,6 @@ var security = (function () {
.Add(copySubjectUserLogonId)
.Add(renameCommonAuthFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
var user = evt.Get("winlog.event_data.SubjectUserName");
if (user) {
Expand All @@ -1748,7 +1726,6 @@ var security = (function () {
.Add(addFailureSubStatus)
.Add(renameCommonAuthFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Build();

var event4672 = new processor.Chain()
Expand All @@ -1762,15 +1739,13 @@ var security = (function () {
evt.Put("winlog.event_data.PrivilegeList", privs.split(/\s+/));
})
.Add(addEventFields)
.Add(addEventOutcome)
.Build();

var event4688 = new processor.Chain()
.Add(copySubjectUser)
.Add(copySubjectUserLogonId)
.Add(renameNewProcessFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
var user = evt.Get("winlog.event_data.TargetUserName");
var res = /^-$/.test(user);
Expand All @@ -1785,7 +1760,6 @@ var security = (function () {
.Add(copySubjectUserLogonId)
.Add(renameCommonAuthFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Build();

var event4697 = new processor.Chain()
Expand All @@ -1794,7 +1768,6 @@ var security = (function () {
.Add(renameCommonAuthFields)
.Add(addServiceFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
evt.AppendTo("event.type", "change");
})
Expand All @@ -1806,7 +1779,6 @@ var security = (function () {
.Add(renameCommonAuthFields)
.Add(addUACDescription)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
var user = evt.Get("winlog.event_data.TargetUserName");
evt.AppendTo('related.user', user);
Expand All @@ -1818,7 +1790,6 @@ var security = (function () {
.Add(copySubjectUser)
.Add(copySubjectUserLogonId)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
var userNew = evt.Get("winlog.event_data.NewTargetUserName");
evt.AppendTo('related.user', userNew);
Expand All @@ -1834,7 +1805,6 @@ var security = (function () {
.Add(copyTargetUserToGroup)
.Add(renameCommonAuthFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
evt.AppendTo("event.type", "group");
var member = evt.Get("winlog.event_data.MemberName");
Expand All @@ -1851,7 +1821,6 @@ var security = (function () {
.Add(copySubjectUserLogonIdFromUserData)
.Add(renameCommonAuthFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
evt.AppendTo("event.type", "change");
})
Expand All @@ -1863,7 +1832,6 @@ var security = (function () {
.Add(renameCommonAuthFields)
.Add(addAuditInfo)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
evt.AppendTo("event.type", "change");
})
Expand All @@ -1872,7 +1840,6 @@ var security = (function () {
var auditLogMgmt = new processor.Chain()
.Add(renameCommonAuthFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Build();

var computerMgmtEvts = new processor.Chain()
Expand All @@ -1882,7 +1849,6 @@ var security = (function () {
.Add(renameCommonAuthFields)
.Add(addUACDescription)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
var privs = evt.Get("winlog.event_data.PrivilegeList");
if (!privs) {
Expand All @@ -1896,14 +1862,12 @@ var security = (function () {
var sessionEvts = new processor.Chain()
.Add(addSessionData)
.Add(addEventFields)
.Add(addEventOutcome)
.Build();

var event4964 = new processor.Chain()
.Add(copyTargetUser)
.Add(copyTargetUserLogonId)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
evt.AppendTo("event.type", "group");
})
Expand All @@ -1916,7 +1880,6 @@ var security = (function () {
.Add(addTicketEncryptionType)
.Add(addTicketStatus)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
var ip = evt.Get("source.ip");
if (/::ffff:/.test(ip)) {
Expand All @@ -1929,14 +1892,12 @@ var security = (function () {
.Add(copyTargetUser)
.Add(addFailureStatus)
.Add(addEventFields)
.Add(addEventOutcome)
.Build();

var scheduledTask = new processor.Chain()
.Add(copySubjectUser)
.Add(copySubjectUserLogonId)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
evt.AppendTo("event.type", "admin");
})
Expand All @@ -1947,7 +1908,6 @@ var security = (function () {
.Add(copySubjectUserLogonId)
.Add(renameCommonAuthFields)
.Add(addEventFields)
.Add(addEventOutcome)
.Add(function(evt) {
var privs = evt.Get("winlog.event_data.PrivilegeList");
if (!privs) {
Expand Down

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