- Home
- Techniques
- Enterprise
- Brute Force
Brute Force
Sub-techniques (4)
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained. Without knowledge of the password for an account or set of accounts, an adversary may systematically guess the password using a repetitive or iterative mechanism. Brute forcing passwords can take place via interaction with a service that will check the validity of those credentials or offline against previously acquired credential data, such as password hashes.
Procedure Examples
| Name | Description |
|---|---|
| APT39 | |
| Chaos |
Chaos conducts brute force attacks against SSH services to gain initial access.[3] |
| DarkVishnya |
DarkVishnya used brute-force attack to obtain login data.[9] |
| FIN5 |
FIN5 has has used the tool GET5 Penetrator to look for remote login and hard-coded credentials.[5][6] |
| OilRig |
OilRig has used brute force techniques to obtain credentials.[7] |
| PoshC2 |
PoshC2 has modules for brute forcing local administrator and AD user accounts.[2] |
| Turla |
Turla may attempt to connect to systems within a victim's network using |
Mitigations
| Mitigation | Description |
|---|---|
| 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. |
| Multi-factor Authentication |
Use multi-factor authentication. Where possible, also enable multi-factor authentication on externally facing services. |
| Password Policies |
Refer to NIST guidelines when creating password policies.[1] |
| User Account Management |
Proactively reset accounts that are known to be part of breached credentials either immediately, or after detecting bruteforce attempts. |
Detection
Monitor authentication logs for system and application login failures of Valid Accounts. If authentication failures are high, then there may be a brute force attempt to gain access to a system using legitimate credentials. Also monitor for many failed authentication attempts across various accounts that may result from password spraying attempts. It is difficult to detect when hashes are cracked, since this is generally done outside the scope of the target network.
References
- Grassi, P., et al. (2017, December 1). SP 800-63-3, Digital Identity Guidelines. Retrieved January 16, 2019.
- Nettitude. (2018, July 23). Python Server for PoshC2. Retrieved April 23, 2019.
- Sebastian Feldmann. (2018, February 14). Chaos: a Stolen Backdoor Rising Again. Retrieved March 5, 2018.
- Kaspersky Lab's Global Research and Analysis Team. (2014, August 7). The Epic Turla Operation: Solving some of the mysteries of Snake/Uroburos. Retrieved December 11, 2014.
- Higgins, K. (2015, October 13). Prolific Cybercrime Gang Favors Legit Login Credentials. Retrieved October 4, 2017.
- Bromiley, M. and Lewis, P. (2016, October 7). Attacking the Hospitality and Gaming Industries: Tracking an Attacker Around the World in 7 Years. Retrieved October 6, 2017.
- Davis, S. and Caban, D. (2017, December 19). APT34 - New Targeted Attack in the Middle East. Retrieved December 20, 2017.
- Hawley et al. (2019, January 29). APT39: An Iranian Cyber Espionage Group Focused on Personal Information. Retrieved February 19, 2019.
- Golovanov, S. (2018, December 6). DarkVishnya: Banks attacked through direct connection to local network. Retrieved May 15, 2020.