{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/clock-manipulation/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":["ESXi"],"_cs_severities":["high"],"_cs_tags":["esxi","clock-manipulation","defense-evasion","ransomware"],"_cs_type":"advisory","_cs_vendors":["VMware"],"content_html":"\u003cp\u003eAttackers may manipulate the system clock on ESXi hosts to hinder forensic investigations, bypass time-based security controls, or disrupt scheduled tasks. This technique is associated with ESXi Post Compromise scenarios and has been observed in connection with Black Basta ransomware. The manipulation involves altering the system time, potentially using the Network Time Protocol (NTP) or other time synchronization mechanisms. Successful clock manipulation allows attackers to obfuscate their activities and complicates incident response efforts. Defenders must monitor for unexpected system clock changes to detect and respond to potential intrusions.\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 ESXi host, possibly through compromised credentials or exploiting a vulnerability.\u003c/li\u003e\n\u003cli\u003eThe attacker authenticates to the ESXi host's management interface (e.g., vSphere Web Client or ESXi Shell).\u003c/li\u003e\n\u003cli\u003eThe attacker executes commands via the ESXi Shell (or a similar interface) to modify the system clock. This often involves using the \u003ccode\u003eesxcli\u003c/code\u003e command or directly interacting with NTP services.\u003c/li\u003e\n\u003cli\u003eThe attacker sets the system clock to a time in the past or future, aiming to invalidate logs or bypass scheduled security checks.\u003c/li\u003e\n\u003cli\u003eThe ESXi host logs the time change event in the system logs, which may include messages referencing \u0026quot;NTPClock\u0026quot; and \u0026quot;system clock stepped.\u0026quot;\u003c/li\u003e\n\u003cli\u003eThe attacker performs malicious activities, such as deploying ransomware or exfiltrating data, under the manipulated timestamp.\u003c/li\u003e\n\u003cli\u003eThe attacker attempts to restore the original time after their activity, to further obscure tracks.\u003c/li\u003e\n\u003cli\u003eThe system continues operating with potentially inaccurate timestamps, impacting logging, security controls, and scheduled tasks.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful clock manipulation on an ESXi host can have severe consequences, potentially affecting dozens or hundreds of virtual machines. Attackers can disrupt backups, invalidate security certificates, and make forensic analysis extremely difficult. In the context of ransomware attacks like Black Basta, manipulating the clock can disrupt recovery processes and exacerbate the damage. This also can hide evidence of malware deployment and data exfiltration.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the provided Sigma rule \u003ccode\u003eESXi System Clock Stepping Detection\u003c/code\u003e to detect significant ESXi system clock changes based on \u003ccode\u003eVMWare ESXi Syslog\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eEnable and monitor \u003ccode\u003eVMWare ESXi Syslog\u003c/code\u003e and integrate with a SIEM for centralized logging and analysis.\u003c/li\u003e\n\u003cli\u003eImplement strict access controls and multi-factor authentication for ESXi host management interfaces to prevent unauthorized clock modifications.\u003c/li\u003e\n\u003cli\u003eInvestigate any alerts generated by the Sigma rule \u003ccode\u003eESXi Clock Manipulation - Statistical Deviation\u003c/code\u003e to identify potential anomalies in ESXi clock behavior.\u003c/li\u003e\n\u003cli\u003eReview historical ESXi system logs for any past instances of clock manipulation, using the search terms specified in the content section of this brief.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-09T10:00:00Z","date_published":"2024-01-09T10:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-09-esxi-clock-manipulation/","summary":"An attacker manipulates the system clock on an ESXi host to potentially evade detection, disrupt logging, or invalidate security controls, as seen in ESXi Post Compromise scenarios and Black Basta ransomware incidents.","title":"ESXi System Clock Manipulation for Evasion","url":"https://feed.craftedsignal.io/briefs/2024-01-09-esxi-clock-manipulation/"}],"language":"en","title":"CraftedSignal Threat Feed - Clock-Manipulation","version":"https://jsonfeed.org/version/1.1"}