Systems and methods for detecting and reacting to malicious activity in computer networks

1. A non-transitory computer readable medium including instructions that, when executed by at least one processor, cause the at least one processor to perform operations for detecting potentially malicious activity, comprising:

receiving data associated with a plurality of authentication messages associated with a ticket requesting client, wherein at least some of the received data includes secure ticket data, the authentication messages having been communicated over a network in accordance with a ticket granting authentication protocol;

analyzing the received data associated with the plurality of authentication messages;

determining, based on the analyzing, a plurality of first characteristics of the data associated with the authentication messages, wherein the first characteristics include the secure ticket data and information identifying the ticket requesting client;

receiving data associated with a new authentication message being communicated over the network and including purported secure ticket data;

determining a plurality of second characteristics of the data associated with the new authentication message, wherein the second characteristics include the purported secure ticket data and information identifying a client associated with the new authentication message;

comparing at least one of the first characteristics with at least one of the second characteristics to determine whether the purported secure ticket data is consistent with the secure ticket data and the client associated with the new authentication message is the same as the ticket requesting client; and

generating, based on the comparison, an assessment of whether the new authentication message is indicative of the potentially malicious activity in the network.

2. The non-transitory computer-readable medium of claim 1 , wherein generating the assessment includes performing a protective false-positive detection operation to limit false-positive indications of potentially malicious activity.

3. The non-transitory computer-readable medium of claim 1 , wherein generating the assessment includes determining whether the data associated with the new authentication message is associated with a potential attack in the network.

4. The non-transitory computer-readable medium of claim 1 , wherein generating the assessment includes determining information containing the potentially malicious activity.

5. The non-transitory computer readable medium of claim 1 , wherein the client associated with the new authentication message is a sender of the new authentication message, and wherein the operations further include identifying a network account associated with the client associated with the new authentication message, and executing a responsive measure with respect to the identified network account.

6. The non-transitory computer-readable medium of claim 1 , wherein the new authentication message is encrypted, and the comparing is based on encrypted data of the new authentication message without first decrypting the encrypted data.

7. The non-transitory computer-readable medium of claim 1 , wherein the comparing includes determining whether at least some of the data associated with the new authentication message matches data of the received data associated with the plurality of authentication messages.

8. The non-transitory computer-readable medium of claim 1 , wherein the comparing includes determining whether the data associated with the new authentication message includes a flag that is not included in the received data associated with the plurality of authentication messages.

9. The non-transitory computer-readable medium of claim 1 , wherein the comparing includes determining whether an encryption type associated with the new authentication message matches an encryption type associated with the plurality of authentication messages.

10. The non-transitory computer-readable medium of claim 1 , wherein the comparing includes determining whether the data associated with the new authentication message includes a ticket that is also included in the received data associated with the plurality of authentication messages.

11. The non-transitory computer-readable medium of claim 1 , wherein the comparing includes:

determining whether the data associated with the new authentication message includes a ticket;

identifying a machine from which the new authentication message originated; and

ascertaining whether the ticket was previously sent to the machine from which the new authentication message originated.

12. The non-transitory computer-readable medium of claim 1 , wherein the comparing includes determining whether an encryption attribute of an authentication message, from the plurality of authentication messages, matches an encryption attribute of the new authentication message.

13. The non-transitory computer-readable medium of claim 1 , wherein the plurality of authentication messages include Kerberos messages and the new authentication message is a Kerberos message.

14. The non-transitory computer-readable medium of claim 1 , the operations further comprising intercepting the new authentication message and determining, based on the generated assessment, whether to transmit the intercepted new authentication message to a target application.

15. The non-transitory computer-readable medium of claim 1 , wherein the plurality of authentication messages include ticket-granting ticket requests.

16. The non-transitory computer-readable medium of claim 1 , wherein the plurality of authentication messages include service ticket requests.

17. A network system configured for detecting potentially malicious activity, the network system comprising:

at least one computer-readable memory storing instructions; and

at least one processor configured to execute the instructions to:

receive data associated with a plurality of authentication messages associated with a ticket requesting client, wherein at least some of the received data includes secure ticket data, the authentication messages having been communicated over a network in accordance with a ticket granting authentication protocol;

analyze the received data associated with the plurality of authentication messages;

determine, based on the analysis, a plurality of first characteristics of the data associated with the authentication messages, wherein the first characteristics include the secure ticket data and information identifying the ticket requesting client;

receive data associated with a new authentication message being communicated over the network and including purported secure ticket data;

determine a plurality of second characteristics of the data associated with the new authentication message, wherein the second characteristics include the purported secure ticket data and information identifying a client associated with the authentication message;

compare at least one of the first characteristics with at least one of the second characteristics to determine whether the purported secure ticket data is consistent with the secure ticket data and the client associated with the new authentication message is the same as the ticket requesting client; and

generate, based on the comparison, an assessment of whether the new authentication message is indicative of the potentially malicious activity in the network.

18. The network system of claim 17 , wherein the generation of the assessment includes performing a protective false-positive detection operation to limit false-positive indications of potentially malicious activity.

19. The network system of claim 17 , wherein the client associated with the new authentication message is a sender of the new authentication message and wherein the at least one processor is further configured to execute the instructions to identify a network account associated with the client associated with a new authentication message, and execute a responsive measure with respect to the identified network account.

20. The network system of claim 17 , wherein the comparison includes a determination of whether at least some of the data associated with the new authentication message matches data of the received data from associated with the plurality of authentication messages.

21. The network system of claim 17 , wherein the comparison includes a determination of whether the data associated with the new authentication message includes a flag that is not included in the received data associated with the plurality of authentication messages.

22. The network system of claim 17 , wherein the comparison includes a determination of whether an encryption type associated with the new authentication message matches an encryption type associated with the plurality of authentication messages.

23. The network system of claim 17 , wherein the plurality of authentication messages include Kerberos messages and the new authentication message is a Kerberos message.

24. The network system of claim 17 , wherein the new authentication message is an intercepted message, such that the generation of the assessment occurs before a determination of whether to transmit the new authentication message to a target application.

25. The network system of claim 17 , wherein the plurality of authentication messages include ticket-granting ticket requests.

26. The network system of claim 17 , wherein the plurality of authentication messages include service ticket requests.

27. A computer-implemented method for performing potentially malicious activity detection operations, comprising:

receiving data associated with a plurality of authentication messages associated with a ticket requesting client, wherein at least some of the received data includes secure ticket data, the authentication messages having been communicated over a network in accordance with a ticket granting authentication protocol;

analyzing the received data associated with the plurality of authentication messages;

determining, based on the analyzing, a plurality of first characteristics of the data associated with the authentication messages, wherein the first characteristics include the secure ticket data and information identifying the ticket requesting client;

receiving data associated with a new authentication message being communicated over the network and including purported secure ticket data;

determining a plurality of second characteristics of the data associated with the new authentication message, wherein the second characteristics include the purported secure ticket data and information identifying a client associated with the new authentication message;

comparing at least one of the first characteristics with at least one of the second characteristics to determine whether the purported secure ticket data is consistent with the secure ticket data and the client associated with the new authentication message is the same as the ticket requesting client; and

generating, based on the comparison, an assessment of whether the new authentication message is indicative of the potentially malicious activity in the network.

28. The computer-implemented method of claim 27 , wherein the comparing includes determining whether an encryption type associated with the new authentication message matches an encryption type associated with the plurality of authentication messages.

29. The computer-implemented method of claim 27 , wherein the comparing includes determining whether the data associated with the new authentication message includes a ticket that is also included in the received data associated with the plurality of authentication messages.

30. The computer-implemented method of claim 27 , wherein the comparing includes:

determining whether the data associated with the new authentication message includes a ticket;

identifying a machine from which the new authentication message originated; and

ascertaining whether the ticket was previously sent to the machine from which the new authentication message originated.