{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/werfault/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":["Elastic Defend","Microsoft Defender XDR"],"_cs_severities":["low"],"_cs_tags":["persistence","registry_modification","werfault"],"_cs_type":"advisory","_cs_vendors":["Microsoft","Elastic","Crowdstrike","SentinelOne"],"content_html":"\u003cp\u003eAttackers can abuse the Windows Error Reporting (Werfault) service to establish persistence on a compromised system. This is achieved by modifying the ReflectDebugger registry key. When Werfault is executed with the \u003ccode\u003e-pr\u003c/code\u003e parameter, it will execute the debugger specified in the ReflectDebugger registry key. This allows attackers to execute arbitrary code every time the Windows Error Reporting utility is triggered. The technique involves modifying specific registry paths associated with the ReflectDebugger. This behavior has been documented as a persistence mechanism in malware analysis reports.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker gains initial access to the system through unspecified means.\u003c/li\u003e\n\u003cli\u003eThe attacker attempts to modify the Windows Error Reporting ReflectDebugger registry key.\u003c/li\u003e\n\u003cli\u003eThe attacker modifies the ReflectDebugger value within one of the following registry paths: \u003ccode\u003eHKLM\\Software\\Microsoft\\Windows\\Windows Error Reporting\\Hangs\\ReflectDebugger\u003c/code\u003e, \u003ccode\u003e\\REGISTRY\\MACHINE\\Software\\Microsoft\\Windows\\Windows Error Reporting\\Hangs\\ReflectDebugger\u003c/code\u003e, or \u003ccode\u003eMACHINE\\Software\\Microsoft\\Windows\\Windows Error Reporting\\Hangs\\ReflectDebugger\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eThe attacker sets the ReflectDebugger value to a malicious executable or script.\u003c/li\u003e\n\u003cli\u003eThe attacker triggers Werfault.exe with the \u003ccode\u003e-pr\u003c/code\u003e parameter, either manually or through a system event.\u003c/li\u003e\n\u003cli\u003eWerfault.exe executes the attacker-controlled code specified in the ReflectDebugger registry value.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves persistence, as the malicious code is executed each time Werfault is triggered with the \u003ccode\u003e-pr\u003c/code\u003e parameter.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation allows attackers to achieve persistence on the targeted system. This can lead to the execution of arbitrary code, potentially resulting in data theft, further malware installation, or complete system compromise. The impact is limited by the permissions of the Werfault process. While no specific victim counts are available, this technique can affect any Windows system where the attacker can modify the registry.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eWerfault ReflectDebugger Registry Modification\u003c/code\u003e to detect unauthorized modifications to the ReflectDebugger registry key (logsource: \u003ccode\u003eregistry_set\u003c/code\u003e, rule title).\u003c/li\u003e\n\u003cli\u003eEnable Sysmon process creation logging to detect the execution of Werfault with the \u003ccode\u003e-pr\u003c/code\u003e parameter.\u003c/li\u003e\n\u003cli\u003eMonitor registry events for changes to the specific ReflectDebugger paths mentioned in the overview section (\u003ccode\u003eHKLM\\Software\\Microsoft\\Windows\\Windows Error Reporting\\Hangs\\ReflectDebugger\u003c/code\u003e).\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-werfault-reflectdebugger-persistence/","summary":"Attackers may establish persistence by modifying the ReflectDebugger registry key associated with Windows Error Reporting to execute arbitrary code when Werfault is invoked with the '-pr' parameter.","title":"Werfault ReflectDebugger Persistence via Registry Modification","url":"https://feed.craftedsignal.io/briefs/2024-01-werfault-reflectdebugger-persistence/"}],"language":"en","title":"CraftedSignal Threat Feed — Werfault","version":"https://jsonfeed.org/version/1.1"}