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Cobalt Strike - Kits

  • Cobalt Strike Community Kit - Community Kit is a central repository of extensions written by the user community to extend the capabilities of Cobalt Strike

Elevate Kit

UAC Token Duplication : Fixed in Windows 10 Red Stone 5 (October 2018)

beacon> runasadmin

Beacon Command Elevators
========================

    Exploit                         Description
    -------                         -----------
    ms14-058                        TrackPopupMenu Win32k NULL Pointer Dereference (CVE-2014-4113)
    ms15-051                        Windows ClientCopyImage Win32k Exploit (CVE 2015-1701)
    ms16-016                        mrxdav.sys WebDav Local Privilege Escalation (CVE 2016-0051)
    svc-exe                         Get SYSTEM via an executable run as a service
    uac-schtasks                    Bypass UAC with schtasks.exe (via SilentCleanup)
    uac-token-duplication           Bypass UAC with Token Duplication

Persistence Kit

  • https://github.com/0xthirteen/MoveKit
  • https://github.com/fireeye/SharPersist 
    # List persistences
SharPersist -t schtaskbackdoor -m list
SharPersist -t startupfolder -m list
SharPersist -t schtask -m list

# Add a persistence
SharPersist -t schtaskbackdoor -c "C:\Windows\System32\cmd.exe" -a "/c calc.exe" -n "Something Cool" -m add
SharPersist -t schtaskbackdoor -n "Something Cool" -m remove

SharPersist -t service -c "C:\Windows\System32\cmd.exe" -a "/c calc.exe" -n "Some Service" -m add
SharPersist -t service -n "Some Service" -m remove

SharPersist -t schtask -c "C:\Windows\System32\cmd.exe" -a "/c calc.exe" -n "Some Task" -m add
SharPersist -t schtask -c "C:\Windows\System32\cmd.exe" -a "/c calc.exe" -n "Some Task" -m add -o hourly
SharPersist -t schtask -n "Some Task" -m remove

Resource Kit

The Resource Kit is Cobalt Strike's means to change the HTA, PowerShell, Python, VBA, and VBS script templates Cobalt Strike uses in its workflows

Artifact Kit

Cobalt Strike uses the Artifact Kit to generate its executables and DLLs. The Artifact Kit is a source code framework to build executables and DLLs that evade some anti-virus products. The Artifact Kit build script creates a folder with template artifacts for each Artifact Kit technique. To use a technique with Cobalt Strike, go to Cobalt Strike -> Script Manager, and load the artifact.cna script from that technique's folder.

Artifact Kit (Cobalt Strike 4.0) - https://www.youtube.com/watch?v=6mC21kviwG4 :

  • Download the artifact kit : Go to Help -> Arsenal to download Artifact Kit (requires a licensed version of Cobalt Strike)
  • Install the dependencies : sudo apt-get install mingw-w64
  • Edit the Artifact code
    • Change pipename strings
    • Change VirtualAlloc in patch.c/patch.exe, e.g: HeapAlloc
    • Change Import
  • Build the Artifact
  • Cobalt Strike -> Script Manager > Load .cna

Mimikatz Kit

  • Download and extract the .tgz from the Arsenal
  • Load the mimikatz.cna aggressor script
  • Use mimikatz functions as normal

Sleep Mask Kit

The Sleep Mask Kit is the source code for the sleep mask function that is executed to obfuscate Beacon, in memory, prior to sleeping.

Use the included build.sh or build.bat script to build the Sleep Mask Kit on Kali Linux or Microsoft Windows. The script builds the sleep mask object file for the three types of Beacons (default, SMB, and TCP) on both x86 and x64 architectures in the sleepmask directory. The default type supports HTTP, HTTPS, and DNS Beacons.

Mutator Kit

The Mutator Kit, introduced by Cobalt Strike, is a tool designed to create uniquely mutated versions of a "sleep mask" used in payloads to evade detection by static signatures. It utilizes LLVM obfuscation techniques to alter the sleep mask, making it difficult for memory scanning tools to identify the mask based on predefined patterns, thereby enhancing operational security for red team activities.

The OBFUSCATIONS variable can be flattening,substitution,split-basic-blocks,bogus.

OBFUSCATIONS=substitution mutator.sh x64 -emit-llvm -S example.c -o example_with_substitutions.ll
mutator.sh x64 -c -DIMPL_CHKSTK_MS=1 -DMASK_TEXT_SECTION=1 -o sleepmask.x64.o src49/sleepmask.c

Thread Stack Spoofer

An advanced in-memory evasion technique that spoofs Thread Call Stack. This technique allows to bypass thread-based memory examination rules and better hide shellcodes while in-process memory.

Thread Stack Spoofer is now enabled by default in the Artifact Kit, it is possible to disable it via the option artifactkit_stack_spoof in the config file arsenal_kit.config.

References