{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/module/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":["Splunk Enterprise","Splunk Enterprise Security","Splunk Cloud"],"_cs_severities":["medium"],"_cs_tags":["powershell","module","dll","filecreation","scriptblocksmuggling"],"_cs_type":"advisory","_cs_vendors":["Splunk"],"content_html":"\u003cp\u003eThe creation of DLL files in PowerShell module directories is a common technique used by attackers to introduce malicious functionality into a system. This activity can be indicative of several malicious behaviors, including the installation of rogue modules, attempts at ScriptBlock smuggling to bypass security controls, or other forms of malicious PowerShell exploitation. The detection focuses on monitoring for the creation of new DLLs within the various PowerShell module directories, which is an unusual event during normal system operation. While legitimate module installations can trigger this alert, the high potential for abuse makes it a critical event to monitor. The detection logic is based on Sysmon Event ID 11.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker gains initial access to the system via phishing or other means.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages PowerShell to download a malicious DLL module.\u003c/li\u003e\n\u003cli\u003eThe attacker uses PowerShell commands to place the malicious DLL into a PowerShell module directory (e.g., \u003ccode\u003eC:\\Windows\\System32\\WindowsPowerShell\\v1.0\\Modules\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eSysmon Event ID 11 logs the creation of the DLL file in the PowerShell module directory.\u003c/li\u003e\n\u003cli\u003eThe attacker then imports the module using \u003ccode\u003eImport-Module\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eOnce the module is imported, the attacker executes malicious code embedded within the DLL.\u003c/li\u003e\n\u003cli\u003eThis allows the attacker to perform actions such as privilege escalation, data exfiltration, or lateral movement.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves persistence by modifying PowerShell profiles or using scheduled tasks to automatically load the malicious module on system startup.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation can lead to a wide range of malicious activities, including persistence, privilege escalation, and data theft. Attackers can use this technique to maintain long-term access to compromised systems and networks. The impact can range from minor data breaches to complete system compromise depending on the attacker\u0026rsquo;s objectives and the permissions of the compromised user account.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eEnable Sysmon Event ID 11 logging to capture file creation events, as this is the data source for the detections below.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026ldquo;PowerShell Module DLL Created\u0026rdquo; to your SIEM and tune for your environment to detect suspicious DLL creation in PowerShell module directories.\u003c/li\u003e\n\u003cli\u003eInvestigate any alerts generated by the Sigma rule to determine if the DLL creation is legitimate or malicious.\u003c/li\u003e\n\u003cli\u003eMonitor PowerShell command-line activity for the use of \u003ccode\u003eImport-Module\u003c/code\u003e and other module-related commands, as these can indicate module loading and execution.\u003c/li\u003e\n\u003cli\u003eImplement application control policies to restrict the execution of unsigned or untrusted DLLs in PowerShell.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"/briefs/2024-01-03-powershell-module-dll-creation/","summary":"The creation of a DLL file within PowerShell module directories can indicate malicious PowerShell activity, such as installing new modules or attempts at ScriptBlock smuggling, and this activity is detected using Sysmon Event ID 11.","title":"Suspicious PowerShell Module DLL Creation","url":"https://feed.craftedsignal.io/briefs/2024-01-03-powershell-module-dll-creation/"}],"language":"en","title":"CraftedSignal Threat Feed — Module","version":"https://jsonfeed.org/version/1.1"}