Wireless Credential Dumping using Netsh Command

This threat brief addresses the abuse of netsh.exe, a legitimate Windows command-line utility, to dump wireless network credentials in clear text. Attackers can exploit this to gain unauthorized access to wireless networks, potentially facilitating lateral movement and data theft. The activity is detected by monitoring process executions for netsh.exe with specific command-line arguments related to wireless LAN (WLAN) profiles and key extraction in clear text. This technique can be employed by both external attackers and malicious insiders to compromise network security. The goal is to obtain saved Wi-Fi passwords, enabling unauthorized network access. This activity can be part of a broader attack campaign, starting from initial access and escalating to sensitive data exfiltration.

Attack Chain

1. The attacker gains initial access to a compromised Windows host.
2. The attacker executes netsh.exe with specific arguments to list available WLAN profiles: netsh wlan show profiles.
3. The attacker uses netsh.exe to dump the wireless key in clear text for a specific profile: netsh wlan show profile name="<profile_name>" key=clear.
4. The command output reveals the clear text password for the targeted Wi-Fi network.
5. The attacker uses the stolen Wi-Fi credentials to connect to the wireless network.
6. Once connected, the attacker performs network reconnaissance to identify valuable targets and resources.
7. The attacker moves laterally through the network, exploiting vulnerabilities or misconfigurations to compromise additional systems.
8. The final objective could include data exfiltration, installation of backdoors, or ransomware deployment.

Impact

Successful exploitation allows unauthorized access to wireless networks, bypassing traditional security measures. This can lead to lateral movement within the network, enabling attackers to access sensitive data, compromise critical systems, and potentially deploy ransomware. The impact ranges from data breaches and financial losses to reputational damage and disruption of services. The severity depends on the sensitivity of the data accessible through the compromised network and the attacker's subsequent actions.

Recommendation

• Deploy the Sigma rule Detect Wireless Credential Dumping via Netsh to identify malicious use of netsh.exe (see "rules" section).
• Enable Sysmon process-creation logging (Event ID 1) to enhance visibility into command-line arguments of executed processes.
• Implement strict access controls and the principle of least privilege to minimize the impact of credential theft.
• Regularly review and update wireless network configurations and passwords to prevent unauthorized access using old credentials.
• Monitor for suspicious network connections originating from systems that have executed netsh.exe with WLAN-related arguments.