{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/actors/blankgrabber-stealer/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":["Multiple threat actors (Azorult","AgentTesla","NjRAT","XMRig","Crypto Stealer","BlankGrabber Stealer)"],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Windows"],"_cs_severities":["high"],"_cs_tags":["taskkill","defense-evasion","windows"],"_cs_type":"threat","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eThis threat brief addresses the excessive use of \u003ccode\u003etaskkill.exe\u003c/code\u003e, a Windows command-line utility, by various threat actors to terminate processes on compromised systems. The observed behavior involves executing \u003ccode\u003etaskkill.exe\u003c/code\u003e more than ten times within a one-minute timeframe. This technique is employed to disable security software, terminate monitoring agents, and halt other critical processes that could hinder the attacker's objectives. The DFIR Report has documented similar tactics in SQL Server attacks, while Joe Sandbox analysis reveals the use of \u003ccode\u003etaskkill.exe\u003c/code\u003e in malicious payloads. Successful execution of this evasion tactic allows attackers to bypass security controls, maintain persistence, and potentially deploy further malicious payloads such as ransomware or data exfiltration tools. This behavior has been associated with multiple malware families including Azorult, AgentTesla, NjRAT, XMRig, Crypto Stealer and BlankGrabber Stealer.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eInitial access is achieved through various means, such as exploiting vulnerabilities or social engineering techniques. (TA0001)\u003c/li\u003e\n\u003cli\u003eThe attacker gains a foothold on the system and executes malicious code, either directly or through a dropper. (TA0002)\u003c/li\u003e\n\u003cli\u003eThe attacker enumerates running processes to identify security tools, monitoring agents, or other critical processes to disable (T1057).\u003c/li\u003e\n\u003cli\u003eThe attacker uses \u003ccode\u003etaskkill.exe\u003c/code\u003e with appropriate arguments to terminate the identified processes. (T1562.001)\u003c/li\u003e\n\u003cli\u003eThe attacker repeats the \u003ccode\u003etaskkill.exe\u003c/code\u003e command multiple times in a short period (more than 10 times within a minute) to ensure the targeted processes are terminated (T1562.001).\u003c/li\u003e\n\u003cli\u003eWith security tools disabled, the attacker proceeds to perform malicious activities, such as data exfiltration or lateral movement. (TA0007, TA0008)\u003c/li\u003e\n\u003cli\u003eThe attacker may install persistence mechanisms to maintain access to the compromised system, taking advantage of the disabled security controls. (TA0003)\u003c/li\u003e\n\u003cli\u003eThe attacker achieves their final objective, such as data theft, ransomware deployment, or disruption of services. (TA0040)\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful execution of this attack can lead to significant disruption and damage. Security tools being disabled results in the system becoming vulnerable to further attacks. Data exfiltration can lead to financial loss and reputational damage. Ransomware deployment can encrypt critical data, causing business interruption and financial loss. While exact victim numbers are unavailable, this technique is associated with multiple malware families, indicating widespread potential impact.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the provided Sigma rule \u003ccode\u003eExcessive Taskkill Execution Count\u003c/code\u003e to detect instances where \u003ccode\u003etaskkill.exe\u003c/code\u003e is executed excessively within a short timeframe.\u003c/li\u003e\n\u003cli\u003eEnable process monitoring with command-line logging to capture the execution of \u003ccode\u003etaskkill.exe\u003c/code\u003e and its arguments, which is required for the Sigma rule to function correctly.\u003c/li\u003e\n\u003cli\u003eInvestigate any alerts generated by the Sigma rule \u003ccode\u003eExcessive Taskkill Execution Count\u003c/code\u003e to determine the legitimacy of the \u003ccode\u003etaskkill.exe\u003c/code\u003e execution and identify potential malicious activity.\u003c/li\u003e\n\u003cli\u003eUse the provided Splunk search query to identify instances of excessive \u003ccode\u003etaskkill.exe\u003c/code\u003e usage in your environment and correlate with other security events to identify potential compromises.\u003c/li\u003e\n\u003cli\u003eImplement network segmentation to limit the impact of lateral movement if an attacker successfully disables security tools.\u003c/li\u003e\n\u003cli\u003eReview and harden endpoint security configurations to prevent attackers from easily disabling security tools.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-03-excessive-taskkill/","summary":"Adversaries use excessive calls to `taskkill.exe` (more than 10 times within a minute) to disable security tools or critical processes, evading detection and compromising systems.","title":"Excessive Taskkill Usage for Defense Evasion","url":"https://feed.craftedsignal.io/briefs/2024-01-03-excessive-taskkill/"}],"language":"en","title":"CraftedSignal Threat Feed - BlankGrabber Stealer)","version":"https://jsonfeed.org/version/1.1"}