The "Nearest Neighborhood" Attack: A Cautionary Tale of Security Oversights

Introduction

While stalking its target, GruesomeLarch performed credential-stuffing attacks that compromised the passwords of several accounts on a web service platform used by the organization’s employees. Two-factor authentication enforced on the platform, however, prevented the attackers from compromising the accounts.

The Attack Unfolds

So GruesomeLarch found devices in physically adjacent locations, compromised them, and used them to probe the target’s Wi-Fi network. It turned out that credentials for the compromised web services accounts also worked for accounts on the Wi-Fi network, only no 2FA was required.

Exploiting a Zero-Day Vulnerability

Adding further flourish, the attackers hacked one of the neighboring Wi-Fi-enabled devices by exploiting what in early 2022 was a zero-day vulnerability in the Microsoft Windows Print Spooler.

The "Nearest Neighborhood" Attack

The Consequences of a Single Oversight

The 2022 hack demonstrates how a single faulty assumption can undo an otherwise effective defense. For whatever reason—likely an assumption that 2FA on the Wi-Fi network was unnecessary because attacks required close proximity—the target deployed 2FA on the Internet-connecting web services platform (Adair isn’t saying what type) but not on the Wi-Fi network. That one oversight ultimately torpedoed a robust security practice.

Conclusion

Advanced persistent threat groups like GruesomeLarch—a part of the much larger GRU APT with names including Fancy Bear, APT28, Forrest Blizzard, and Sofacy—excel in finding and exploiting these sorts of oversights.

FAQs

Q: What is the "Nearest Neighborhood" attack?
A: The "Nearest Neighborhood" attack is a type of attack where an attacker compromises a device in a physically adjacent location to access a target’s Wi-Fi network.

Q: What is GruesomeLarch?
A: GruesomeLarch is an advanced persistent threat group (APT) that is part of the larger GRU APT.

Q: What is the significance of this attack?
A: The attack demonstrates how a single oversight in security can compromise even the most robust defenses.

Q: What can be done to prevent such attacks?
A: Implementing 2FA on all networks, not just those connecting to the internet, and regularly updating software to prevent exploitation of zero-day vulnerabilities can help prevent such attacks.