improved token management #996

MrAle98 · 2022-11-09T14:37:47Z

Card

I noticed there are some issues in token management, in particular when it comes to creating a sacrificial logon session with make-token command. With this PR I may have solved the issue by forcing the goroutine to use always the same thread, in which it was called ImpersonateLoggedOnUser, only when necessary. In addition i modified the Rev2Self to also close the Handle to the token.

Details

If you try to run make-token and then rubeus --in-process triage you may notice that the LUID showed in the rubeus command changes unexpectedly.
Here an example:

sliver (SYMBOLIC_FLAME) > rubeus --in-process triage

[*] Tasked beacon SYMBOLIC_FLAME (4af33f0f)

[+] SYMBOLIC_FLAME completed task 4af33f0f

[*] rubeus output:

   ______        _
  (_____ \      | |
   _____) )_   _| |__  _____ _   _  ___
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0x91bb1

 ---------------------------------------------------------------------------------------------------------------------
 | LUID    | UserName                      | Service                                          | EndTime              |
 ---------------------------------------------------------------------------------------------------------------------
 | 0x91bb1 | nonPrivileged @ CONTOSO.LOCAL | krbtgt/CONTOSO.LOCAL                             | 11/9/2022 7:05:57 PM |
 | 0x91bb1 | nonPrivileged @ CONTOSO.LOCAL | LDAP/WIN-ICSQJ44N1F3.contoso.local/contoso.local | 11/9/2022 7:05:57 PM |
 ---------------------------------------------------------------------------------------------------------------------



sliver (SYMBOLIC_FLAME) > make-token -d CONTOSO -u user -p pass

[*] Tasked beacon SYMBOLIC_FLAME (636b9d85)

[+] SYMBOLIC_FLAME completed task 636b9d85



sliver (SYMBOLIC_FLAME) > rubeus --in-process triage

[*] Tasked beacon SYMBOLIC_FLAME (c5acf5d4)

[+] SYMBOLIC_FLAME completed task c5acf5d4

[*] rubeus output:

   ______        _
  (_____ \      | |
   _____) )_   _| |__  _____ _   _  ___
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0x522b1c

 ---------------------------------------
 | LUID | UserName | Service | EndTime |
 ---------------------------------------
 ---------------------------------------



sliver (SYMBOLIC_FLAME) > rubeus --in-process triage

[*] Tasked beacon SYMBOLIC_FLAME (fcacb96f)

[+] SYMBOLIC_FLAME completed task fcacb96f

[*] rubeus output:

   ______        _
  (_____ \      | |
   _____) )_   _| |__  _____ _   _  ___
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0x522b1c

 ---------------------------------------
 | LUID | UserName | Service | EndTime |
 ---------------------------------------
 ---------------------------------------



sliver (SYMBOLIC_FLAME) > rubeus --in-process triage

[*] Tasked beacon SYMBOLIC_FLAME (23bdad73)

[+] SYMBOLIC_FLAME completed task 23bdad73

[*] rubeus output:

   ______        _
  (_____ \      | |
   _____) )_   _| |__  _____ _   _  ___
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0x91bb1

 ---------------------------------------------------------------------------------------------------------------------
 | LUID    | UserName                      | Service                                          | EndTime              |
 ---------------------------------------------------------------------------------------------------------------------
 | 0x91bb1 | nonPrivileged @ CONTOSO.LOCAL | krbtgt/CONTOSO.LOCAL                             | 11/9/2022 7:05:57 PM |
 | 0x91bb1 | nonPrivileged @ CONTOSO.LOCAL | LDAP/WIN-ICSQJ44N1F3.contoso.local/contoso.local | 11/9/2022 7:05:57 PM |
 ---------------------------------------------------------------------------------------------------------------------



sliver (SYMBOLIC_FLAME) >

As you can see before make-token LUID is 0x91bb1. After running make-token a new LUID is created 0x522b1c running rubeus first time. The third time after make-token instead rubeus shows again that the LUID is 0x91bb1.
This probably happens because the goroutine executing the handler gets assigned a random thread. In order to solve the issue I use runtime.LockOSThread() in order to bound the goroutine to the same thread. Before calling runtime.LockOSThread() ImpersonateLoggedOnUser in order to set the token in the goroutine thread. The bounding of the goroutine to the same thread with runtime.LockOSThread() is applied only for sysHandlers when the variable priv.CurrenToken is different from 0.
With the modification in the PR here is the behaviour:

[server] sliver (VISUAL_SWATH) > rubeus -E -M --in-process triage

[*] Tasked beacon VISUAL_SWATH (fb1f829c)

[+] VISUAL_SWATH completed task fb1f829c

[*] rubeus output:

   ______        _                      
  (_____ \      | |                     
   _____) )_   _| |__  _____ _   _  ___ 
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1 


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0x91bb1

 ---------------------------------------------------------------------------------------------------------------------- 
 | LUID    | UserName                      | Service                                          | EndTime               |
 ---------------------------------------------------------------------------------------------------------------------- 
 | 0x91bb1 | nonPrivileged @ CONTOSO.LOCAL | krbtgt/CONTOSO.LOCAL                             | 11/9/2022 10:17:32 PM |
 | 0x91bb1 | nonPrivileged @ CONTOSO.LOCAL | LDAP/WIN-ICSQJ44N1F3.contoso.local/contoso.local | 11/9/2022 10:17:32 PM |
 ---------------------------------------------------------------------------------------------------------------------- 



[server] sliver (VISUAL_SWATH) > make-token -d CONTOSO -u user -p pass

[*] Tasked beacon VISUAL_SWATH (81e2e5b1)

[+] VISUAL_SWATH completed task 81e2e5b1



[server] sliver (VISUAL_SWATH) > rubeus --in-process triage

[*] Tasked beacon VISUAL_SWATH (da81fa98)

[+] VISUAL_SWATH completed task da81fa98

[*] rubeus output:

   ______        _                      
  (_____ \      | |                     
   _____) )_   _| |__  _____ _   _  ___ 
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1 


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0xa71711

 --------------------------------------- 
 | LUID | UserName | Service | EndTime |
 --------------------------------------- 
 --------------------------------------- 



[server] sliver (VISUAL_SWATH) > rubeus --in-process triage

[*] Tasked beacon VISUAL_SWATH (7e9a436a)

[+] VISUAL_SWATH completed task 7e9a436a

[*] rubeus output:

   ______        _                      
  (_____ \      | |                     
   _____) )_   _| |__  _____ _   _  ___ 
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1 


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0xa71711

 --------------------------------------- 
 | LUID | UserName | Service | EndTime |
 --------------------------------------- 
 --------------------------------------- 



[server] sliver (VISUAL_SWATH) > rubeus --in-process triage

[*] Tasked beacon VISUAL_SWATH (c58005ac)

[+] VISUAL_SWATH completed task c58005ac

[*] rubeus output:

   ______        _                      
  (_____ \      | |                     
   _____) )_   _| |__  _____ _   _  ___ 
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1 


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0xa71711

 --------------------------------------- 
 | LUID | UserName | Service | EndTime |
 --------------------------------------- 
 --------------------------------------- 



[server] sliver (VISUAL_SWATH) > rubeus --in-process triage

[*] Tasked beacon VISUAL_SWATH (087100d7)

[+] VISUAL_SWATH completed task 087100d7

[*] rubeus output:


[server] sliver (VISUAL_SWATH) > rubeus --in-process triage

[*] Tasked beacon VISUAL_SWATH (70d40f14)

[+] VISUAL_SWATH completed task 70d40f14

[*] rubeus output:

   ______        _                      
  (_____ \      | |                     
   _____) )_   _| |__  _____ _   _  ___ 
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1 


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0xa71711

 --------------------------------------- 
 | LUID | UserName | Service | EndTime |
 --------------------------------------- 
 --------------------------------------- 



[server] sliver (VISUAL_SWATH) > rubeus --in-process triage

[*] Tasked beacon VISUAL_SWATH (b774e545)

[+] VISUAL_SWATH completed task b774e545

[*] rubeus output:

   ______        _                      
  (_____ \      | |                     
   _____) )_   _| |__  _____ _   _  ___ 
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1 


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0xa71711

 --------------------------------------- 
 | LUID | UserName | Service | EndTime |
 --------------------------------------- 
 --------------------------------------- 


   ______        _                      
  (_____ \      | |                     
   _____) )_   _| |__  _____ _   _  ___ 
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1 


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0xa71711

 --------------------------------------- 
 | LUID | UserName | Service | EndTime |
 --------------------------------------- 
 --------------------------------------- 



[server] sliver (VISUAL_SWATH) > rev2self

[*] Tasked beacon VISUAL_SWATH (51ac314f)

[+] VISUAL_SWATH completed task 51ac314f


[server] sliver (VISUAL_SWATH) > rubeus --in-process triage

[*] Tasked beacon VISUAL_SWATH (7a730884)

[+] VISUAL_SWATH completed task 7a730884

[*] rubeus output:

   ______        _                      
  (_____ \      | |                     
   _____) )_   _| |__  _____ _   _  ___ 
  |  __  /| | | |  _ \| ___ | | | |/___)
  | |  \ \| |_| | |_) ) ____| |_| |___ |
  |_|   |_|____/|____/|_____)____/(___/

  v2.0.1 


Action: Triage Kerberos Tickets (Current User)

[*] Current LUID    : 0x91bb1

 ---------------------------------------------------------------------------------------------------------------------- 
 | LUID    | UserName                      | Service                                          | EndTime               |
 ---------------------------------------------------------------------------------------------------------------------- 
 | 0x91bb1 | nonPrivileged @ CONTOSO.LOCAL | krbtgt/CONTOSO.LOCAL                             | 11/9/2022 10:17:32 PM |
 | 0x91bb1 | nonPrivileged @ CONTOSO.LOCAL | LDAP/WIN-ICSQJ44N1F3.contoso.local/contoso.local | 11/9/2022 10:17:32 PM |
 ---------------------------------------------------------------------------------------------------------------------- 



[server] sliver (VISUAL_SWATH) >

You can see now that after make-token, when rubeus --in-process triage is executed the LUID remains 0xa71711. After rev2self the LUID displayed is the previous one.

In addition I've modified Rev2Self so that it closes the handle to the token, while I introduced TRev2Self that just calls syscalls.RevToSelf() from win32 API.

rkervella · 2022-11-09T16:28:08Z

Thanks, completely forgot to use runtime.LockOSThread in this case.

improved token management

5e6148b

MrAle98 requested a review from a team as a code owner November 9, 2022 14:37

rkervella approved these changes Nov 9, 2022

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rkervella merged commit c7e77c8 into BishopFox:master Nov 9, 2022

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improved token management #996

improved token management #996

MrAle98 commented Nov 9, 2022 •

edited

rkervella commented Nov 9, 2022

improved token management #996

improved token management #996

Conversation

MrAle98 commented Nov 9, 2022 • edited

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rkervella commented Nov 9, 2022

MrAle98 commented Nov 9, 2022 •

edited