{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/post-exploitation/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["netexec","crackmapexec","lateral-movement","post-exploitation","hacktool"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eNetExec (formerly CrackMapExec) is a widely used post-exploitation tool favored by penetration testers and malicious actors for Active Directory enumeration, credential harvesting, and remote code execution. When executed on a Windows system, NetExec extracts its embedded data files into a temporary directory named \u0026ldquo;_MEI\u0026rdquo; followed by a random string, located under the user\u0026rsquo;s Temp folder. A specific subdirectory, \u0026ldquo;\\nxc\\data\u0026quot;, within this extraction path contains files unique to NetExec. These file creation events offer a reliable indicator for detecting NetExec execution on a host. This activity is important for defenders as it signals potential reconnaissance, lateral movement attempts, or the establishment of a foothold within the network.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker gains initial access to a system through various means (e.g., compromised credentials, exploiting a vulnerability).\u003c/li\u003e\n\u003cli\u003eThe attacker uploads the NetExec executable (nxc.exe) to the compromised host.\u003c/li\u003e\n\u003cli\u003eThe attacker executes nxc.exe.\u003c/li\u003e\n\u003cli\u003eNetExec extracts its embedded data files into a temporary directory. The path follows the pattern: \u003ccode\u003e\\Temp\\_MEI\u0026lt;random\u0026gt;\\\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eWithin the temporary directory, a specific subdirectory \u003ccode\u003e\\nxc\\data\\\u003c/code\u003e is created, containing NetExec\u0026rsquo;s data files.\u003c/li\u003e\n\u003cli\u003eNetExec utilizes these files for Active Directory enumeration, credential harvesting, and reconnaissance activities.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages gathered information to move laterally within the network, potentially targeting other systems or services.\u003c/li\u003e\n\u003cli\u003eThe attacker may attempt to execute code remotely using harvested credentials, furthering their access and control within the environment.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful NetExec deployment can lead to extensive reconnaissance of Active Directory environments, enabling attackers to map out network infrastructure, identify valuable targets, and harvest credentials. This can result in unauthorized access to sensitive data, lateral movement to critical systems, and ultimately, a complete compromise of the domain. Organizations in all sectors are vulnerable, with the impact ranging from data breaches and financial loss to reputational damage and operational disruption.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the provided Sigma rule \u003ccode\u003eDetect NetExec File Creation\u003c/code\u003e to your SIEM to detect NetExec\u0026rsquo;s unique file creation patterns (logsource: file_event, product: windows).\u003c/li\u003e\n\u003cli\u003eMonitor file creation events in the \u003ccode\u003e\\Temp\u003c/code\u003e directory for filenames containing \u003ccode\u003e_MEI\u003c/code\u003e and \u003ccode\u003e\\nxc\\data\\\u003c/code\u003e, as these indicate NetExec\u0026rsquo;s extraction process.\u003c/li\u003e\n\u003cli\u003eEnable process-creation logging with command-line arguments to identify the execution of \u003ccode\u003enxc.exe\u003c/code\u003e (logsource: process_creation, product: windows).\u003c/li\u003e\n\u003cli\u003eInvestigate any alerts generated by these rules to determine the extent of the compromise and contain any further lateral movement.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-18T12:00:00Z","date_published":"2024-01-18T12:00:00Z","id":"/briefs/2024-01-netexec-file-indicators/","summary":"This brief covers the detection of NetExec, a post-exploitation and lateral movement tool, through monitoring for unique file creation patterns associated with its execution and file extraction in Windows environments.","title":"NetExec File Creation Detection","url":"https://feed.craftedsignal.io/briefs/2024-01-netexec-file-indicators/"},{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["pentest","post-exploitation","lateral-movement","active-directory"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eNetExec, previously known as CrackMapExec, is a post-exploitation tool commonly used during Active Directory penetration testing. It is also favored by red teams and malicious actors for reconnaissance, lateral movement, and credential harvesting within Windows networks. This tool allows for the enumeration of hosts, exploitation of network services, and remote command execution. The use of NetExec in an enterprise environment is considered suspicious due to its capabilities for identifying vulnerable systems and facilitating unauthorized access. Defenders should monitor for its execution, as it is often a precursor to more serious attacks, including ransomware deployment, such as the Lynx ransomware.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker gains initial access to a Windows system via an exploit or compromised credentials.\u003c/li\u003e\n\u003cli\u003eNetExec (nxc.exe) is deployed on the compromised host, often copied to a temporary directory.\u003c/li\u003e\n\u003cli\u003eNetExec is executed with commands to enumerate network shares and identify potential targets using SMB.\u003c/li\u003e\n\u003cli\u003eThe tool uses LDAP to query Active Directory for user accounts, groups, and organizational units.\u003c/li\u003e\n\u003cli\u003eNetExec attempts to authenticate to other systems using gathered or compromised credentials via protocols such as SMB, SSH, or RDP.\u003c/li\u003e\n\u003cli\u003eSuccessful authentication allows for remote command execution via WMI or WinRM.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages identified vulnerabilities or misconfigurations to escalate privileges on the target systems.\u003c/li\u003e\n\u003cli\u003eThe attacker moves laterally through the network, gaining access to sensitive data or deploying ransomware like Lynx.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful execution of NetExec can lead to widespread compromise within an Active Directory environment. Attackers can identify and exploit vulnerable systems, harvest credentials, and move laterally to gain access to critical assets. This can result in data theft, system disruption, and ransomware deployment, potentially affecting hundreds or thousands of systems depending on the size of the organization. The tool is often used as a precursor to ransomware attacks, where entire networks can be encrypted, leading to significant financial and reputational damage.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eHackTool - NetExec Execution\u003c/code\u003e to your SIEM to detect the execution of NetExec based on process creation logs.\u003c/li\u003e\n\u003cli\u003eMonitor process creation events for \u003ccode\u003enxc.exe\u003c/code\u003e with command-line arguments associated with network protocols like \u003ccode\u003eftp\u003c/code\u003e, \u003ccode\u003eldap\u003c/code\u003e, \u003ccode\u003emssql\u003c/code\u003e, \u003ccode\u003enfs\u003c/code\u003e, \u003ccode\u003erdp\u003c/code\u003e, \u003ccode\u003esmb\u003c/code\u003e, \u003ccode\u003essh\u003c/code\u003e, \u003ccode\u003evnc\u003c/code\u003e, \u003ccode\u003ewinrm\u003c/code\u003e, and \u003ccode\u003ewmi\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eImplement strict access controls and regularly audit Active Directory to minimize the potential for lateral movement.\u003c/li\u003e\n\u003cli\u003eConsider using application control solutions to prevent the execution of unauthorized tools like \u003ccode\u003enxc.exe\u003c/code\u003e.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T14:35:00Z","date_published":"2024-01-03T14:35:00Z","id":"/briefs/2024-01-netexec-execution/","summary":"The threat brief details the detection of NetExec (formerly CrackMapExec), a post-exploitation tool used for Active Directory penetration testing and network enumeration, often employed by threat actors for lateral movement and credential harvesting.","title":"Detection of NetExec Hacktool Execution","url":"https://feed.craftedsignal.io/briefs/2024-01-netexec-execution/"}],"language":"en","title":"CraftedSignal Threat Feed — Post-Exploitation","version":"https://jsonfeed.org/version/1.1"}