How do attackers breach a secure organization without stepping foot inside? In the Nearest Neighbor Attack, the Russian APT group Fancy Bear(also known as APT28) [2] executed a sophisticated cyber-espionage campaign, exploiting weak Wi-Fi security and nearby organizations to infiltrate their ultimate target.

This wasn’t just a typical hacking attempt—it was a carefully planned operation. The attackers:

• Stole credentials using password-spraying.
• Exploited Wi-Fi networks that lacked multi-factor authentication (MFA).
• Leveraged systems in neighboring organizations to bypass physical distance.
• Extracted sensitive data while leaving minimal traces.

Here’s a high-level overview of the attack path:

Now, let’s break down the attack path [1]. 

1. Initial Recon and Credential Harvesting

• Objective: Gain access credentials to Organization A’s network.
• Method:
• Conducted password-spraying attacks on public-facing services of Organization A.
• Successfully brute-forced several valid username-password combinations.
• Public-facing services were protected by multi-factor authentication (MFA), which prevented immediate use of these credentials.

2. Exploiting Wi-Fi Network Vulnerabilities

• Gap Exploited: Organization A’s enterprise Wi-Fi network required only a valid domain username and password for access, without MFA.
• Challenge for Attackers: The attackers were geographically distant and could not directly connect to Organization A’s Wi-Fi.

3. Compromising Neighboring Organizations

• Strategy:
• Identified and targeted nearby organizations (Organization B, Organization C) geographically close to Organization A.
• Breached these organizations through:
• Exploiting vulnerable public-facing services.
• Using compromised credentials obtained via brute force or phishing.
• Focused on finding dual-homed systems—devices connected to both wired and Wi-Fi networks.

4. Leveraging Dual-Homed Systems

• Execution:
• Attackers gained control of a dual-homed system within Organization B.
• Used its Wi-Fi adapter to connect to Organization A’s Wi-Fi network, leveraging previously brute-forced credentials.
• Bypassed physical proximity limitations by daisy-chaining through compromised neighboring networks.

5. Gaining Access to Organization A’s Network

• Connection Established: Successfully authenticated into Organization A’s Wi-Fi network.
• Network Penetration:
• Gained access to the internal network.
• Began reconnaissance to locate sensitive data.

6. Privilege Escalation

• Zero-Day Exploitation: Used a privilege escalation vulnerability (CVE-2022-38028) in the Microsoft Windows Print Spooler.
• Persistence Established:
• Deployed tools like servtask.bat to dump sensitive registry hives (SAM, SECURITY, and SYSTEM).
• Used PowerShell scripts to compress and stage data for exfiltration.

7. Lateral Movement and Data Exfiltration

• Objective: Access sensitive Ukraine-related projects and data.
• Techniques:
• Moved laterally across systems to identify valuable data.
• Used living-off-the-land tools to avoid detection (e.g., netsh for port-forwarding, vssadmin for creating shadow copies).
• Exfiltrated data via:
• SMB connections.
• Staging data on public-facing systems for external download.

8. Anti-Forensic Measures

• Covering Tracks:
• Used Windows utility Cipher.exe to securely delete files.
• Removed all artifacts related to tools and scripts after use.
• Minimal malware deployment to evade endpoint detection.

9. Further Intrusions via Guest Wi-Fi

• Post-Detection Activity: After initial remediation by Organization A, attackers pivoted to the guest Wi-Fi network.
• Exploit: Poor segmentation allowed access to internal systems from the guest network.
• Reinfiltration: Attackers regained access to sensitive data before being detected again.

Citation 

1. Koessel, S., Adair, S., & Lancaster, T. (2024, November 22). The nearest neighbor attack: How a Russian APT weaponized nearby Wi-Fi networks for covert access. Volexity. https://www.volexity.com/blog/2024/11/22/the-nearest-neighbor-attack-how-a-russian-apt-weaponized-nearby-wi-fi-networks-for-covert-access/

2. CrowdStrike. (2019, February 12). Who is FANCY BEAR (APT28)? CrowdStrike. https://www.crowdstrike.com/blog/who-is-fancy-bear/