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Sigma Aggregation rule fixes (#622) (#639)
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Signed-off-by: Subhobrata Dey <sbcd90@gmail.com>
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@opensearch-trigger-bot
opensearch-trigger-bot[bot] committed Oct 4, 2023
1 parent 032509d commit f733685
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Showing 16 changed files with 240 additions and 35 deletions.
13 changes: 10 additions & 3 deletions src/main/java/org/opensearch/securityanalytics/findings/FindingsService.java
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Expand Up @@ -59,7 +59,6 @@ public void getFindingsByDetectorId(String detectorId, Table table, ActionListen
public void onResponse(GetDetectorResponse getDetectorResponse) {
// Get all monitor ids from detector
Detector detector = getDetectorResponse.getDetector();
List<String> monitorIds = detector.getMonitorIds();
ActionListener<GetFindingsResponse> getFindingsResponseListener = new ActionListener<>() {
@Override
public void onResponse(GetFindingsResponse resp) {
Expand Down Expand Up @@ -87,12 +86,20 @@ public void onFailure(Exception e) {
// monitor --> detectorId mapping
Map<String, Detector> monitorToDetectorMapping = new HashMap<>();
detector.getMonitorIds().forEach(
monitorId -> monitorToDetectorMapping.put(monitorId, detector)
monitorId -> {
if (detector.getRuleIdMonitorIdMap().containsKey("chained_findings_monitor")) {
if (!detector.getRuleIdMonitorIdMap().get("chained_findings_monitor").equals(monitorId)) {
monitorToDetectorMapping.put(monitorId, detector);
}
} else {
monitorToDetectorMapping.put(monitorId, detector);
}
}
);
// Get findings for all monitor ids
FindingsService.this.getFindingsByMonitorIds(
monitorToDetectorMapping,
monitorIds,
new ArrayList<>(monitorToDetectorMapping.keySet()),
DetectorMonitorConfig.getAllFindingsIndicesPattern(detector.getDetectorType()),
table,
getFindingsResponseListener
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1 change: 1 addition & 0 deletions src/main/java/org/opensearch/securityanalytics/model/Rule.java
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Expand Up @@ -481,6 +481,7 @@ public List<AggregationItem> getAggregationItemsFromRule () throws SigmaError {
for (SigmaCondition condition: sigmaRule.getDetection().getParsedCondition()) {
Pair<ConditionItem, AggregationItem> parsedItems = condition.parsed();
AggregationItem aggItem = parsedItems.getRight();
aggItem.setTimeframe(sigmaRule.getDetection().getTimeframe());
aggregationItems.add(aggItem);
}
return aggregationItems;
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10 changes: 10 additions & 0 deletions src/main/java/org/opensearch/securityanalytics/rules/aggregation/AggregationItem.java
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,8 @@ public class AggregationItem implements Serializable {

private Double threshold;

private String timeframe;

public void setAggFunction(String aggFunction) {
this.aggFunction = aggFunction;
}
Expand Down Expand Up @@ -59,4 +61,12 @@ public void setThreshold(Double threshold) {
public Double getThreshold() {
return threshold;
}

public void setTimeframe(String timeframe) {
this.timeframe = timeframe;
}

public String getTimeframe() {
return timeframe;
}
}
4 changes: 2 additions & 2 deletions src/main/java/org/opensearch/securityanalytics/rules/backend/OSQueryBackend.java
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Original file line number Diff line number Diff line change
Expand Up @@ -381,10 +381,10 @@ public AggregationQueries convertAggregation(AggregationItem aggregation) {
fmtAggQuery = String.format(Locale.getDefault(), aggCountQuery, "result_agg", aggregation.getGroupByField());
}
aggBuilder.field(fieldName);
fmtBucketTriggerQuery = String.format(Locale.getDefault(), bucketTriggerQuery, "_cnt", "_cnt", "result_agg", "_cnt", aggregation.getCompOperator(), aggregation.getThreshold());
fmtBucketTriggerQuery = String.format(Locale.getDefault(), bucketTriggerQuery, "_cnt", "_count", "result_agg", "_cnt", aggregation.getCompOperator(), aggregation.getThreshold());

Script script = new Script(String.format(Locale.getDefault(), bucketTriggerScript, "_cnt", aggregation.getCompOperator(), aggregation.getThreshold()));
condition = new BucketSelectorExtAggregationBuilder(bucketTriggerSelectorId, Collections.singletonMap("_cnt", "_cnt"), script, "result_agg", null);
condition = new BucketSelectorExtAggregationBuilder(bucketTriggerSelectorId, Collections.singletonMap("_cnt", "_count"), script, "result_agg", null);
} else {
fmtAggQuery = String.format(Locale.getDefault(), aggQuery, "result_agg", aggregation.getGroupByField(), aggregation.getAggField(), aggregation.getAggFunction(), aggregation.getAggField());
fmtBucketTriggerQuery = String.format(Locale.getDefault(), bucketTriggerQuery, aggregation.getAggField(), aggregation.getAggField(), "result_agg", aggregation.getAggField(), aggregation.getCompOperator(), aggregation.getThreshold());
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1 change: 1 addition & 0 deletions src/main/java/org/opensearch/securityanalytics/rules/backend/QueryBackend.java
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Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,7 @@ public List<Object> convertRule(SigmaRule rule) throws SigmaError {
}
queries.add(query);
if (aggItem != null) {
aggItem.setTimeframe(rule.getDetection().getTimeframe());
queries.add(convertAggregation(aggItem));
}
}
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16 changes: 14 additions & 2 deletions src/main/java/org/opensearch/securityanalytics/rules/objects/SigmaDetections.java
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Original file line number Diff line number Diff line change
Expand Up @@ -21,11 +21,14 @@ public class SigmaDetections {

private List<String> condition;

private String timeframe;

private List<SigmaCondition> parsedCondition;

public SigmaDetections(Map<String, SigmaDetection> detections, List<String> condition) throws SigmaDetectionError {
public SigmaDetections(Map<String, SigmaDetection> detections, List<String> condition, String timeframe) throws SigmaDetectionError {
this.detections = detections;
this.condition = condition;
this.timeframe = timeframe;

if (this.detections.isEmpty()) {
throw new SigmaDetectionError("No detections defined in Sigma rule");
Expand Down Expand Up @@ -55,7 +58,12 @@ protected static SigmaDetections fromDict(Map<String, Object> detectionMap) thro
}
}

return new SigmaDetections(detections, conditionList);
String timeframe = null;
if (detectionMap.containsKey("timeframe")) {
timeframe = detectionMap.get("timeframe").toString();
}

return new SigmaDetections(detections, conditionList, timeframe);
}

public Map<String, SigmaDetection> getDetections() {
Expand All @@ -69,4 +77,8 @@ public List<String> getCondition() {
public List<SigmaCondition> getParsedCondition() {
return parsedCondition;
}

public String getTimeframe() {
return timeframe;
}
}
6 changes: 4 additions & 2 deletions src/main/java/org/opensearch/securityanalytics/transport/TransportIndexDetectorAction.java
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Original file line number Diff line number Diff line change
Expand Up @@ -90,6 +90,7 @@
import org.opensearch.securityanalytics.model.DetectorTrigger;
import org.opensearch.securityanalytics.model.Rule;
import org.opensearch.securityanalytics.model.Value;
import org.opensearch.securityanalytics.rules.aggregation.AggregationItem;
import org.opensearch.securityanalytics.rules.backend.OSQueryBackend;
import org.opensearch.securityanalytics.rules.backend.OSQueryBackend.AggregationQueries;
import org.opensearch.securityanalytics.rules.backend.QueryBackend;
Expand Down Expand Up @@ -784,7 +785,8 @@ private IndexMonitorRequest createBucketLevelMonitorRequest(

List<String> indices = detector.getInputs().get(0).getIndices();

AggregationQueries aggregationQueries = queryBackend.convertAggregation(rule.getAggregationItemsFromRule().get(0));
AggregationItem aggItem = rule.getAggregationItemsFromRule().get(0);
AggregationQueries aggregationQueries = queryBackend.convertAggregation(aggItem);

SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder()
.seqNoAndPrimaryTerm(true)
Expand Down Expand Up @@ -814,7 +816,7 @@ private IndexMonitorRequest createBucketLevelMonitorRequest(
? new BoolQueryBuilder()
: QueryBuilders.boolQuery().must(searchSourceBuilder.query());
RangeQueryBuilder timeRangeFilter = QueryBuilders.rangeQuery(TIMESTAMP_FIELD_ALIAS)
.gt("{{period_end}}||-1h")
.gt("{{period_end}}||-" + (aggItem.getTimeframe() != null? aggItem.getTimeframe(): "1h"))
.lte("{{period_end}}")
.format("epoch_millis");
boolQueryBuilder.must(timeRangeFilter);
Expand Down
2 changes: 1 addition & 1 deletion src/main/java/org/opensearch/securityanalytics/util/RuleIndices.java
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Original file line number Diff line number Diff line change
Expand Up @@ -300,7 +300,7 @@ private List<Rule> getQueries(QueryBackend backend, String category, List<String

Rule ruleModel = new Rule(
rule.getId().toString(), NO_VERSION, rule, category,
ruleQueries,
ruleQueries.stream().map(Object::toString).collect(Collectors.toList()),
new ArrayList<>(queryFieldNames),
ruleStr
);
Expand Down
30 changes: 30 additions & 0 deletions src/test/java/org/opensearch/securityanalytics/TestHelpers.java
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Original file line number Diff line number Diff line change
Expand Up @@ -88,6 +88,11 @@ public static Detector randomDetectorWithTriggers(List<String> rules, List<Detec
rules.stream().map(DetectorRule::new).collect(Collectors.toList()));
return randomDetector(null, null, null, List.of(input), triggers, null, null, null, null);
}
public static Detector randomDetectorWithTriggersAndScheduleAndEnabled(List<String> rules, List<DetectorTrigger> triggers, Schedule schedule, boolean enabled) {
DetectorInput input = new DetectorInput("windows detector for security analytics", List.of("windows"), Collections.emptyList(),
rules.stream().map(DetectorRule::new).collect(Collectors.toList()));
return randomDetector(null, null, null, List.of(input), triggers, schedule, enabled, null, null);
}

public static Detector randomDetectorWithTriggers(List<String> rules, List<DetectorTrigger> triggers, String detectorType, DetectorInput input) {
return randomDetector(null, detectorType, null, List.of(input), triggers, null, null, null, null);
Expand Down Expand Up @@ -352,6 +357,7 @@ public static String productIndexMaxAggRule() {

public static String randomProductDocument(){
return "{\n" +
" \"name\": \"laptop\",\n" +
" \"fieldA\": 123,\n" +
" \"mappedB\": 111,\n" +
" \"fieldC\": \"valueC\"\n" +
Expand Down Expand Up @@ -563,6 +569,9 @@ public static String netFlowMappings() {

public static String productIndexMapping(){
return "\"properties\":{\n" +
" \"name\":{\n" +
" \"type\":\"keyword\"\n" +
" },\n" +
" \"fieldA\":{\n" +
" \"type\":\"long\"\n" +
" },\n" +
Expand Down Expand Up @@ -591,13 +600,32 @@ public static String productIndexAvgAggRule(){
" category: test_category\n" +
" product: test_product\n" +
" detection:\n" +
" timeframe: 5m\n" +
" sel:\n" +
" fieldA: 123\n" +
" fieldB: 111\n" +
" fieldC: valueC\n" +
" condition: sel | avg(fieldA) by fieldC > 110";
}

public static String productIndexCountAggRule(){
return " title: Test\n" +
" id: 39f918f3-981b-4e6f-a975-8af7e507ef2b\n" +
" status: test\n" +
" level: critical\n" +
" description: Detects QuarksPwDump clearing access history in hive\n" +
" author: Florian Roth\n" +
" date: 2017/05/15\n" +
" logsource:\n" +
" category: test_category\n" +
" product: test_product\n" +
" detection:\n" +
" timeframe: 5m\n" +
" sel:\n" +
" name: laptop\n" +
" condition: sel | count(*) by name > 2";
}

public static String randomAggregationRule(String aggFunction, String signAndValue) {
String rule = "title: Remote Encrypting File System Abuse\n" +
"id: 5f92fff9-82e2-48eb-8fc1-8b133556a551\n" +
Expand All @@ -619,6 +647,7 @@ public static String randomAggregationRule(String aggFunction, String signAndVa
" category: application\n" +
" definition: 'Requirements: install and apply the RPC Firewall to all processes with \"audit:true action:block uuid:df1941c5-fe89-4e79-bf10-463657acf44d or c681d488-d850-11d0-8c52-00c04fd90f7e'\n" +
"detection:\n" +
" timeframe: 5m\n" +
" sel:\n" +
" Opcode: Info\n" +
" condition: sel | %s(SeverityValue) by Version %s\n" +
Expand Down Expand Up @@ -649,6 +678,7 @@ public static String randomAggregationRule(String aggFunction, String signAndVa
" category: application\n" +
" definition: 'Requirements: install and apply the RPC Firewall to all processes with \"audit:true action:block uuid:df1941c5-fe89-4e79-bf10-463657acf44d or c681d488-d850-11d0-8c52-00c04fd90f7e'\n" +
"detection:\n" +
" timeframe: 5m\n" +
" sel:\n" +
" Opcode: %s\n" +
" condition: sel | %s(SeverityValue) by Version %s\n" +
Expand Down
15 changes: 4 additions & 11 deletions src/test/java/org/opensearch/securityanalytics/resthandler/DetectorMonitorRestApiIT.java
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Original file line number Diff line number Diff line change
Expand Up @@ -1483,7 +1483,7 @@ public void testCreateDetector_verifyWorkflowExecutionBucketLevelDocLevelMonitor
Map<String, Object> getFindingsBody = entityAsMap(getFindingsResponse);

assertNotNull(getFindingsBody);
assertEquals(10, getFindingsBody.get("total_findings"));
assertEquals(6, getFindingsBody.get("total_findings"));

String findingDetectorId = ((Map<String, Object>)((List)getFindingsBody.get("findings")).get(0)).get("detectorId").toString();
assertEquals(detectorId, findingDetectorId);
Expand All @@ -1495,7 +1495,6 @@ public void testCreateDetector_verifyWorkflowExecutionBucketLevelDocLevelMonitor
List<Map<String, Object>> findings = (List)getFindingsBody.get("findings");

Set<String> docLevelRules = new HashSet<>(List.of(randomDocRuleId));
List<String> bucketLevelMonitorFindingDocs = new ArrayList<>();
for(Map<String, Object> finding : findings) {
List<Map<String, Object>> queries = (List<Map<String, Object>>) finding.get("queries");
Set<String> findingRules = queries.stream().map(it -> it.get("id").toString()).collect(Collectors.toSet());
Expand All @@ -1504,16 +1503,10 @@ public void testCreateDetector_verifyWorkflowExecutionBucketLevelDocLevelMonitor
docLevelFinding.addAll((List<String>) finding.get("related_doc_ids"));
} else {
List<String> findingDocs = (List<String>) finding.get("related_doc_ids");
if (((Map<String, Object>) ((List<Object>) finding.get("queries")).get(0)).get("query").equals("_id:*")) {
Assert.assertEquals(1, findingDocs.size());
bucketLevelMonitorFindingDocs.addAll(findingDocs);
} else {
Assert.assertEquals(4, findingDocs.size());
assertTrue(Arrays.asList("1", "2", "3", "4").containsAll(findingDocs));
}
Assert.assertEquals(4, findingDocs.size());
assertTrue(Arrays.asList("1", "2", "3", "4").containsAll(findingDocs));
}
}
assertTrue(bucketLevelMonitorFindingDocs.containsAll(Arrays.asList("1", "2", "3", "4")));
// Verify doc level finding
assertTrue(Arrays.asList("1", "2", "3", "4", "5").containsAll(docLevelFinding));
}
Expand Down Expand Up @@ -1652,7 +1645,7 @@ public void testCreateDetector_verifyWorkflowExecutionMultipleBucketLevelDocLeve

// Assert findings
assertNotNull(getFindingsBody);
assertEquals(33, getFindingsBody.get("total_findings"));
assertEquals(19, getFindingsBody.get("total_findings"));
}


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