Valid Accounts

During the 2015 Ukraine Electric Power Attack, Sandworm Team used valid accounts on the corporate network to escalate privileges, move laterally, and establish persistence within the corporate network. ^[4]

Akira uses valid account information to remotely access victim networks, such as VPN credentials.^[5][6]

APT18 actors leverage legitimate credentials to log into external remote services.^[7]

APT28 has used legitimate credentials to gain initial access, maintain access, and exfiltrate data from a victim network. The group has specifically used credentials stolen through a spearphishing email to login to the DCCC network. The group has also leveraged default manufacturer's passwords to gain initial access to corporate networks via IoT devices such as a VOIP phone, printer, and video decoder.^{[8][9][10][11]}

APT29 has used a compromised account to access an organization's VPN infrastructure.^[12]

APT33 has used valid accounts for initial access and privilege escalation.^[13][14]

APT39 has used stolen credentials to compromise Outlook Web Access (OWA).^[15]

APT41 used compromised credentials to log on to other systems.^[16][17]

Axiom has used previously compromised administrative accounts to escalate privileges.^[18]

During the C0032 campaign, TEMP.Veles used compromised VPN accounts.^[19]

Carbanak actors used legitimate credentials of banking employees to perform operations that sent them millions of dollars.^[20]

Chimera has used a valid account to maintain persistence via scheduled task.^[21]

Cinnamon Tempest has used compromised user accounts to deploy payloads and create system services.^[22]

Dragonfly has compromised user credentials and used valid accounts for operations.^[23][24][25]

Dtrack used hard-coded credentials to gain access to a network share.^[26]

Adversaries can instruct Duqu to spread laterally by copying itself to shares it has enumerated and for which it has obtained legitimate credentials (via keylogging or other means). The remote host is then infected by using the compromised credentials to schedule a task on remote machines that executes the malware.^[27]

FIN10 has used stolen credentials to connect remotely to victim networks using VPNs protected with only a single factor.^[28]

FIN4 has used legitimate credentials to hijack email communications.^[29][30]

FIN5 has used legitimate VPN, RDP, Citrix, or VNC credentials to maintain access to a victim environment.^[31][32][33]

To move laterally on a victim network, FIN6 has used credentials stolen from various systems on which it gathered usernames and password hashes.^[34][35][36]

FIN7 has harvested valid administrative credentials for lateral movement.^[37]

FIN8 has used valid accounts for persistence and lateral movement.^[38]

Fox Kitten has used valid credentials with various services during lateral movement.^[39]

GALLIUM leveraged valid accounts to maintain access to a victim network.^[40]

During HomeLand Justice, threat actors used a compromised Exchange account to search mailboxes and create new Exchange accounts.^[41]

INC Ransom has used compromised valid accounts for access to victim environments.^{[42][43][44][45]}

Indrik Spider has used valid accounts for initial access and lateral movement.^[46] Indrik Spider has also maintained access to the victim environment through the VPN infrastructure.^[46]

Industroyer can use supplied user credentials to execute processes and stop services.^[47]

Ke3chang has used credential dumpers or stealers to obtain legitimate credentials, which they used to gain access to victim accounts.^[48]

Kinsing has used valid SSH credentials to access remote hosts.^[49]

LAPSUS$ has used compromised credentials and/or session tokens to gain access into a victim's VPN, VDI, RDP, and IAMs.^[50][51]

Lazarus Group has used administrator credentials to gain access to restricted network segments.^[52]

Leviathan has obtained valid accounts to gain initial access.^[53][54]

Linux Rabbit acquires valid SSH accounts through brute force. ^[55]

menuPass has used valid accounts including shared between Managed Service Providers and clients to move between the two environments.^{[56][57][58][59]}

During Night Dragon, threat actors used compromised VPN accounts to gain access to victim systems.^[60]

OilRig has used compromised credentials to access other systems on a victim network.^{[61][62][17][63]}

During Operation Wocao, threat actors used valid VPN credentials to gain initial access.^[64]

PittyTiger attempts to obtain legitimate credentials during operations.^[65]

Play has used valid VPN accounts to achieve initial access.^[66]

POLONIUM has used valid compromised credentials to gain access to victim environments.^[67]

Sandworm Team have used previously acquired legitimate credentials prior to attacks.^[68]

Some SeaDuke samples have a module to extract email from Microsoft Exchange servers using compromised credentials.^[69]

Silence has used compromised credentials to log on to other systems and escalate privileges.^[70]

Silent Librarian has used compromised credentials to obtain unauthorized access to online accounts.^[71]

During the SolarWinds Compromise, APT29 used different compromised credentials for remote access and to move laterally.^[72][73][74]

Star Blizzard has used stolen credentials to sign into victim email accounts.^[75][76]

Suckfly used legitimate account credentials that they dumped to navigate the internal victim network as though they were the legitimate account owner.^[77]

Threat Group-3390 actors obtain legitimate credentials using a variety of methods and use them to further lateral movement on victim networks.^[78]

Volt Typhoon relies primarily on valid credentials for persistence.^[79]

Wizard Spider has used valid credentials for privileged accounts with the goal of accessing domain controllers.^[80][81]

Use conditional access policies to block logins from non-compliant devices or from outside defined organization IP ranges.^[82]

Disable legacy authentication, which does not support MFA, and require the use of modern authentication protocols instead.

Ensure that applications do not store sensitive data or credentials insecurely. (e.g. plaintext credentials in code, published credentials in repositories, or credentials in public cloud storage).

Implement multi-factor authentication (MFA) across all account types, including default, local, domain, and cloud accounts, to prevent unauthorized access, even if credentials are compromised. MFA provides a critical layer of security by requiring multiple forms of verification beyond just a password. This measure significantly reduces the risk of adversaries abusing valid accounts to gain initial access, escalate privileges, maintain persistence, or evade defenses within your network.

Applications and appliances that utilize default username and password should be changed immediately after the installation, and before deployment to a production environment.^[83] When possible, applications that use SSH keys should be updated periodically and properly secured.

Policies should minimize (if not eliminate) reuse of passwords between different user accounts, especially employees using the same credentials for personal accounts that may not be defended by enterprise security resources.

Audit domain and local accounts as well as their permission levels routinely to look for situations that could allow an adversary to gain wide access by obtaining credentials of a privileged account. ^{[3] [84]} These audits should also include if default accounts have been enabled, or if new local accounts are created that have not been authorized. Follow best practices for design and administration of an enterprise network to limit privileged account use across administrative tiers. ^[85]

Regularly audit user accounts for activity and deactivate or remove any that are no longer needed.

Applications may send push notifications to verify a login as a form of multi-factor authentication (MFA). Train users to only accept valid push notifications and to report suspicious push notifications.