Password Spraying Attacks: Detection and Defense Mechanisms

It is important to note that given the nature of password spraying attacks, you cannot prevent them, but you can detect and stop them in their tracks. This blog post describes how this type of attack unfolds, how to detect ongoing attacks, and how to reduce the risk of becoming the next victim.

Password Spraying Attacks: Detection and Defense Mechanisms

What is a Password Spraying Attack?

A typical brute force attack targets a single account and attempts multiple passwords to gain access. Modern cybersecurity protocols can detect this suspicious activity and lock the account if there are too many failed login attempts in a short period.

Password Spraying, however, is trying to log in to multiple user accounts with many common passwords. Trying one password at a time on many different accounts bypasses the standard lockdown protocol. It allows an attacker to try more and more passwords before being detected or blocked. Unfortunately, password spraying attacks are often successful because many users do not follow password best practices. The top 200 passwords leaked in a data breach in 2019 contained obvious combinations of numbers such as "12345" and the word "password" itself.

Casting a wide net can have at least some success, but today's knowledgeable threat actors rely on a more accurate approach. They usually set their sights on users who use single sign-on authentication (SSO), hoping that they will infer credentials that will allow access to multiple systems or applications. They also often target users with cloud services and federated authentication applications. Federation authentication helps mask malicious traffic, so this approach can allow a threat actor to move laterally.

If a password spraying attack compromises an account, the victim may experience a temporary or permanent loss of sensitive information. A successful attack can mean business disruption, significant loss of revenue, and loss of reputation for an organisation.

How to Detect a Password Spraying Attack

While traditional measures may not automatically detect password spraying attacks, there are some reliable indicators to watch out for. The most obvious are numerous authentication attempts in a short period of time, especially those that fail due to incorrect passwords. Of course, a closely related indicator is the increase in account bans.

Password spraying attacks also often lead to a sudden increase in login attempts affecting SSO portals or cloud applications. Threat actors can use automated tools to perform thousands of login attempts in a short amount of time. Often, these attempts come from a single IP address or device (Though they could employ measures to switch up IPs).

How to Reduce the Risk of Becoming the Next Victim

While it is important to identify successful attacks immediately, it can be devastating to allow an attacker even to access sensitive data for a short period of time. A healthy cybersecurity strategy requires a comprehensive and proactive approach that guarantees layered protection to block as many attacks as possible. Be sure to follow the following best practices:

  • Require multi-factor authentication for all users.
  • Develop a secure password strategy for shared accounts.
  • Establish a robust password reset policy after account lockout.
  • Conduct regular user awareness training to ensure that all users understand the threat of password spraying and how to develop and maintain strong passwords.