{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/regasm/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["RegAsm"],"_cs_severities":["high"],"_cs_tags":["regasm","process-injection","defense-evasion","windows"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eThe detection analytic identifies instances where regasm.exe is executed without command-line arguments. This behavior is suspicious because RegAsm (Assembly Registration Tool) typically requires arguments specifying which assemblies to register or unregister. The absence of command-line arguments often indicates that the process has been injected into by another process, and its normal execution flow has been altered to evade standard defenses. The detection focuses on endpoint telemetry related to process execution, parent-child relationships, and command-line parameters. It is crucial for defenders because successful exploitation can lead to arbitrary code execution within a trusted process.\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 through an unspecified method.\u003c/li\u003e\n\u003cli\u003eThe attacker injects malicious code into a running process or spawns a new process (e.g., PowerShell).\u003c/li\u003e\n\u003cli\u003eThe injected code identifies and targets regasm.exe for process injection.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the process injection technique to execute regasm.exe without command-line arguments.\u003c/li\u003e\n\u003cli\u003eRegAsm, now running without arguments, may execute attacker-controlled code due to the injected malicious payload.\u003c/li\u003e\n\u003cli\u003eThe injected code performs malicious actions such as modifying system configurations, creating persistence mechanisms, or escalating privileges.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the compromised process to move laterally within the network and access sensitive data.\u003c/li\u003e\n\u003cli\u003eThe final objective could be data exfiltration, system disruption, or deployment of ransomware.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation can allow attackers to execute arbitrary code within the context of a trusted system process, potentially bypassing application control policies and detection mechanisms. This can lead to privilege escalation, persistence, lateral movement, and data compromise. While the exact number of victims and sectors targeted are unknown, any environment where RegAsm is present is potentially vulnerable, especially developer workstations and servers.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rules in this brief to your SIEM to detect instances of RegAsm executing without command-line arguments and tune for your environment.\u003c/li\u003e\n\u003cli\u003eEnable Sysmon process-creation logging to provide the necessary telemetry for the detection rules.\u003c/li\u003e\n\u003cli\u003eInvestigate any detected instances of RegAsm executing without arguments to determine the root cause and scope of the compromise.\u003c/li\u003e\n\u003cli\u003eReview and harden endpoint security policies to prevent process injection attacks.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-09T12:00:00Z","date_published":"2024-01-09T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-09-regasm-no-args/","summary":"The execution of regasm.exe without command-line arguments is often indicative of process injection and potential code execution, which could lead to privilege escalation, persistence, or data compromise.","title":"RegAsm Executed Without Command Line Arguments","url":"https://feed.craftedsignal.io/briefs/2024-01-09-regasm-no-args/"}],"language":"en","title":"CraftedSignal Threat Feed - RegAsm","version":"https://jsonfeed.org/version/1.1"}