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<p class="MsoNormal">Hi all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am trying to identify a port scan event.<o:p></o:p></p>
<p class="MsoPlainText">The basic fact is connection log. For each combination of src (source IP) and dst (destination IP) , detect a port scan event, if over 60 seconds there were at least 20 connection logs with different service and protocol.<o:p></o:p></p>
<p class="MsoPlainText">The event will stay closed for 10 minute - no event will be sent during this time for this combination of src and dst. The event will contain the connection logs’ ids (markers).<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">I tried to implement it using “accumulate” and “over window:time” but it consumes too much memory.
<o:p></o:p></p>
<p class="MsoNormal">So I am trying to imitate this functionality using several rules and facts.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My drl contains the following lines (among others):<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">declare CorrelatedEvent<o:p></o:p></p>
<p class="MsoNormal"> @role( event)<o:p></o:p></p>
<p class="MsoNormal"> @expires( 600s )<o:p></o:p></p>
<p class="MsoNormal">end<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">declare CandidatesWindow<o:p></o:p></p>
<p class="MsoNormal"> @role( event)<o:p></o:p></p>
<p class="MsoNormal"> @expires( 60s )<o:p></o:p></p>
<p class="MsoNormal">end<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">rule "Create Port Scan Event - 1"<o:p></o:p></p>
<p class="MsoNormal">enabled true<o:p></o:p></p>
<p class="MsoNormal">dialect "java" <o:p></o:p></p>
<p class="MsoNormal">no-loop <o:p></o:p></p>
<p class="MsoNormal">when<o:p></o:p></p>
<p class="MsoNormal"> $log : Log()<o:p></o:p></p>
<p class="MsoNormal"> not CorrelatedEvent(getId() == "portScan" , groupByFieldsMap.get("src") == $log.fieldsMap.get("src") ,groupByFieldsMap.get("dst") == $log.fieldsMap.get("dst"))<o:p></o:p></p>
<p class="MsoNormal"> $windows : ArrayList()<o:p></o:p></p>
<p class="MsoNormal"> from collect( CandidatesWindow(getRuleId() == "portScan" , groupByFieldsMap.get("src") == $log.fieldsMap.get("src") , groupByFieldsMap.get("dst") == $log.fieldsMap.get("dst")))<o:p></o:p></p>
<p class="MsoNormal">then<o:p></o:p></p>
<p class="MsoNormal"> String id = $log.fieldsMap.get("port").toString();<o:p></o:p></p>
<p class="MsoNormal"> System.out.println(new Date().toString()+" windowSize: " + $windows.size());<o:p></o:p></p>
<p class="MsoNormal"> for (Object windowObj : $windows) {<o:p></o:p></p>
<p class="MsoNormal"> CandidatesWindow window = (CandidatesWindow) windowObj;<o:p></o:p></p>
<p class="MsoNormal"> modify ( window ) { addLog($log, id) }<o:p></o:p></p>
<p class="MsoNormal"> }<o:p></o:p></p>
<p class="MsoNormal"> CandidatesWindow newWindow = new CandidatesWindow("portScan", true);<o:p></o:p></p>
<p class="MsoNormal"> newWindow.groupByFieldsMap.put("src", $log.fieldsMap.get("src"));<o:p></o:p></p>
<p class="MsoNormal"> newWindow.groupByFieldsMap.put("dst", $log.fieldsMap.get("dst"));<o:p></o:p></p>
<p class="MsoNormal"> newWindow.addLog($log, id);<o:p></o:p></p>
<p class="MsoNormal"> insert(newWindow);<o:p></o:p></p>
<p class="MsoNormal">end<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This imitates sliding time windows. <o:p></o:p></p>
<p class="MsoNormal">when I tested it, I got the following exception:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Exception executing consequence for rule "Create Port Scan Event - 1" in com.checkpoint.correlation.impl.drools.package1: java.util.ConcurrentModificationException<o:p></o:p></p>
<p class="MsoNormal"> at org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)<o:p></o:p></p>
<p class="MsoNormal"> at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1297)<o:p></o:p></p>
<p class="MsoNormal"> at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1221)<o:p></o:p></p>
<p class="MsoNormal"> at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1456)<o:p></o:p></p>
<p class="MsoNormal"> at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:710)<o:p></o:p></p>
<p class="MsoNormal"> at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:674)<o:p></o:p></p>
<p class="MsoNormal"> at org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:230)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.impl.drools.DroolsCEPEngineV1.insertEvents(DroolsCEPEngineV1.java:173)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.impl.feeder.JsonFileFeeder.init(JsonFileFeeder.java:68)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.server.CorrelationServer.initFeeder(CorrelationServer.java:63)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.server.CorrelationServer.run(CorrelationServer.java:28)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.server.CorrelationServer.runServer(CorrelationServer.java:101)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.server.CorrelationServer.main(CorrelationServer.java:85)<o:p></o:p></p>
<p class="MsoNormal">Caused by: java.util.ConcurrentModificationException<o:p></o:p></p>
<p class="MsoNormal"> at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:819)<o:p></o:p></p>
<p class="MsoNormal"> at java.util.ArrayList$Itr.next(ArrayList.java:791)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.impl.drools.package1.Rule_Create_Port_Scan_Event___1_2f94bc67f9064c6e9614982cf9bc8859.defaultConsequence(Rule_Create_Port_Scan_Event___1_2f94bc67f9064c6e9614982cf9bc8859.java:11)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.impl.drools.package1.Rule_Create_Port_Scan_Event___1_2f94bc67f9064c6e9614982cf9bc8859DefaultConsequenceInvokerGenerated.evaluate(Unknown Source)<o:p></o:p></p>
<p class="MsoNormal"> at com.checkpoint.correlation.impl.drools.package1.Rule_Create_Port_Scan_Event___1_2f94bc67f9064c6e9614982cf9bc8859DefaultConsequenceInvoker.evaluate(Unknown Source)<o:p></o:p></p>
<p class="MsoNormal"> at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1287)<o:p></o:p></p>
<p class="MsoNormal"> ... 11 more<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It is caused by modify ( window ) in the for loop.<o:p></o:p></p>
<p class="MsoNormal">How can I make it work?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks.<o:p></o:p></p>
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