Erinevus lehekülje "Itx8071-task2" redaktsioonide vahel

Allikas: Kursused
Mine navigeerimisribale Mine otsikasti
(Lehekülg asendatud tekstiga 'To be announced.')
Märgis: Asendamine
 
(ei näidata sama kasutaja 55 vahepealset redaktsiooni)
1. rida: 1. rida:
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This homework assignment requires the knowledge from Modules 6 and 7.
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To be announced.
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==== Create SEC rules that accomplish the following event correlation task: ====
 
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===== 1) Monitor sshd log events and detect SSH probing from remote hosts, where the same non-existing user account is probed over SSH from 3 distinct IP addresses within 60 seconds or less. =====
 
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For example, suppose the following events appear in the log:
 
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Nov  7 12:53:11 myhost sshd[10477]: Failed password for invalid user admin2 from 10.3.6.22 port 50087 ssh2
 
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Nov  7 12:53:12 myhost sshd[10477]: Failed password for invalid user admin2 from 10.3.6.22 port 50087 ssh2
 
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Nov  7 12:53:39 myhost sshd[10479]: Failed password for invalid user oracle from 10.3.6.24 port 9899 ssh2
 
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Nov  7 12:53:40 myhost sshd[10479]: Failed password for invalid user oracle from 10.3.6.24 port 9899 ssh2
 
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Nov  7 12:54:01 myhost sshd[10527]: Failed publickey for invalid user admin2 from 10.1.2.52 port 40106 ssh2
 
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Nov  7 12:54:02 myhost sshd[10527]: Failed publickey for invalid user admin2 from 10.1.2.52 port 40106 ssh2
 
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Nov  7 12:54:07 myhost sshd[10543]: Failed password for invalid user admin2 from 10.17.8.9 port 32444 ssh2
 
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When above events appear, SSH probing for non-existing use admin2 should be detected, since this user was probed between 12:53:11 and 12:54:07 from 3 distinct IP addresses 10.3.6.22, 10.1.2.52 and 10.17.8.9.
 
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Also note that the detection should be done with a sliding window approach -- if the counting operation for some non-existing user has not seen enough events during 60 seconds, the 60 second detection window should be moved forward.
 
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2) If the previous condition has been detected for 3 distinct non-existing users during 900 seconds (for example, admin2, oracle and testuser3 have been probed within 900 seconds), report this event to the local root-user via e-mail. After an e-mail has been sent, ensure than no repeated e-mails are generated during the following 3600 seconds.
 
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==== Some hints for accomplishing this assignment: ====
 
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* don't try to solve the whole assignment with just one rule, but rather write several rules which interact,
 
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* if SSH probing for some non-existing user account is detected (as described in the first subtask), you could generate a relevant synthetic event for this user, in order to provide input for further event correlation rules.
 
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* all parts of the solution must be fully functional even when several non-existing user accounts are probed from several hosts in parallel (for example, contexts maintained by different counting operations must not interfere with each other).
 
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Apart from studying the examples from the course slides, have a look at the SEC man page (installed at the virtual machines or found at https://simple-evcorr.github.io/man.html).
 

Viimane redaktsioon: 22. august 2026, kell 16:12

To be announced.