EXPLORE DETECTIONS
ESXi Malicious VIB Forced Install
Detects potentially malicious installation of VMware Installation Bundles (VIBs) using the --force flag. The --force option bypasses signature and compatibility checks, allowing unsigned, community-supported, or incompatible VIBs to be installed on an ESXi host. This behavior is uncommon in normal administrative operations and is often observed in post-compromise scenarios where adversaries attempt to install backdoored or unauthorized kernel modules, drivers, or monitoring tools to establish persistence or gain deeper control of the hypervisor.
ESXi Reverse Shell Patterns
This detection looks for reverse shell string patterns on an ESXi host, which may indicate that a threat actor is attempting to establish remote control over the system.
ESXi Sensitive Files Accessed
This detection identifies access to sensitive system and configuration files on an ESXi host, including authentication data, service configurations, and VMware-specific management settings. Interaction with these files may indicate adversary reconnaissance, credential harvesting, or preparation for privilege escalation, lateral movement, or persistence.
ESXi Shared or Stolen Root Account
This detection monitors for signs of a shared or potentially compromised root account on ESXi hosts by tracking the number of unique IP addresses logging in as root within a short time window. Multiple logins from different IPs in a brief period may indicate credential misuse, lateral movement, or account compromise.
ESXi Shell Access Enabled
This detection identifies when the ESXi Shell is enabled on a host, which may indicate that a malicious actor is preparing to execute commands locally or establish persistent access. Enabling the shell outside of approved maintenance windows can be a sign of compromise or unauthorized administrative activity.
ESXi SSH Brute Force
This detection identifies signs of SSH brute-force attacks by monitoring for a high number of failed login attempts within a short time frame. Such activity may indicate an attacker attempting to gain unauthorized access through password guessing.
ESXi SSH Enabled
This detection identifies SSH being enabled on ESXi hosts, which can be an early indicator of malicious activity. Threat actors often use SSH to gain persistent remote access after compromising credentials or exploiting vulnerabilities.
ESXi Syslog Config Change
This detection identifies changes to the syslog configuration on an ESXi host using esxcli, which may indicate an attempt to disrupt log collection and evade detection.
ESXi System Clock Manipulation
This detection identifies a significant change to the system clock on an ESXi host, which may indicate an attempt to manipulate timestamps and evade detection or forensic analysis
ESXi System Information Discovery
This detection identifies the use of ESXCLI system-level commands that retrieve configuration details. While used for legitimate administration, this behavior may also indicate adversary reconnaissance aimed at profiling the ESXi host's capabilities, build information, or system role in preparation for further compromise.
ESXi User Granted Admin Role
This detection identifies when a user is granted the Administrator role on an ESXi host. Assigning elevated privileges is a critical action that can indicate potential malicious behavior if performed unexpectedly. Adversaries who gain access may use this to escalate privileges, maintain persistence, or disable security controls.
ESXi VIB Acceptance Level Tampering
This detection identifies changes to the VIB (vSphere Installation Bundle) acceptance level on an ESXi host. Modifying the acceptance level, such as setting it to CommunitySupported, lowers the system's integrity enforcement and may allow the installation of unsigned or unverified software.
ESXi VM Discovery
This detection identifies the use of ESXCLI commands to discover virtual machines on an ESXi host While used by administrators, this activity may also indicate adversary reconnaissance aimed at identifying high value targets, mapping the virtual environment, or preparing for data theft or destructive operations.
ESXi VM Exported via Remote Tool
This detection identifies the use of a remote tool to download virtual machine disk files from a datastore. The NFC protocol is used by management tools to transfer files to and from ESXi hosts, but it can also be abused by attackers or insiders to exfiltrate full virtual disk images
ETW Registry Disabled
The following analytic detects a registry modification that disables the ETW for the .NET Framework. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the ETWEnabled registry value under the .NETFramework path. This activity is significant because disabling ETW can allow attackers to evade Endpoint Detection and Response (EDR) tools and hide their execution from audit logs. If confirmed malicious, this action could enable attackers to operate undetected, potentially leading to further compromise and persistent access within the environment.
Eventvwr UAC Bypass
The following analytic detects an Eventvwr UAC bypass by identifying suspicious registry modifications in the path that Eventvwr.msc references upon execution. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry changes and process execution details. This activity is significant because it indicates a potential privilege escalation attempt, allowing an attacker to execute arbitrary commands with elevated privileges. If confirmed malicious, this could lead to unauthorized code execution, persistence, and further compromise of the affected system.
Excessive Attempt To Disable Services
The following analytic identifies a suspicious series of command-line executions attempting to disable multiple services. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes where "sc.exe" is used with parameters like "config" or "Disabled" within a short time frame. This activity is significant as it may indicate an adversary's attempt to disable security or other critical services to further compromise the system. If confirmed malicious, this could lead to the attacker achieving persistence, evading detection, or disabling security mechanisms, thereby increasing the risk of further exploitation.
Excessive distinct processes from Windows Temp
The following analytic identifies an excessive number of distinct processes executing from the Windows\Temp directory. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process paths and counts within a 20-minute window. This behavior is significant as it often indicates the presence of post-exploit frameworks like Koadic and Meterpreter, which use this technique to execute malicious actions. If confirmed malicious, this activity could allow attackers to execute arbitrary code, escalate privileges, and maintain persistence within the environment, posing a severe threat to system integrity and security.
Excessive DNS Failures
The following analytic identifies excessive DNS query failures by counting DNS responses that do not indicate success, triggering when there are more than 50 occurrences. It leverages the Network_Resolution data model, focusing on DNS reply codes that signify errors. This activity is significant because a high number of DNS failures can indicate potential network misconfigurations, DNS poisoning attempts, or malware communication issues. If confirmed malicious, this activity could lead to disrupted network services, hindered communication, or data exfiltration attempts by attackers.
Excessive File Deletion In WinDefender Folder
The following analytic detects excessive file deletion events in the Windows Defender folder. It leverages Sysmon EventCodes 23 and 26 to identify processes deleting multiple files within this directory. This behavior is significant as it may indicate an attempt to corrupt or disable Windows Defender, a key security component. If confirmed malicious, this activity could allow an attacker to disable endpoint protection, facilitating further malicious actions without detection.
Excessive number of service control start as disabled
The following analytic detects an excessive number of `sc.exe` processes launched with the command line argument `start= disabled` within a short period. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, command-line executions, and process GUIDs. This activity is significant as it may indicate an attempt to disable critical services, potentially impairing system defenses. If confirmed malicious, this behavior could allow an attacker to disrupt security mechanisms, hinder incident response, and maintain control over the compromised system.
Excessive number of taskhost processes
The following analytic identifies an excessive number of taskhost.exe and taskhostex.exe processes running within a short time frame. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and their counts. This behavior is significant as it is commonly associated with post-exploitation tools like Meterpreter and Koadic, which use multiple instances of these processes for actions such as discovery and lateral movement. If confirmed malicious, this activity could indicate an ongoing attack, allowing attackers to execute code, escalate privileges, or move laterally within the network.
Excessive Usage Of Cacls App
The following analytic identifies excessive usage of `cacls.exe`, `xcacls.exe`, or `icacls.exe` to change file or folder permissions. It looks for 10 or more execution of the aforementioned processes in the span of 1 minute. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as it may indicate an adversary attempting to restrict access to malware components or artifacts on a compromised system. If confirmed malicious, this behavior could prevent users from deleting or accessing critical files, aiding in the persistence and concealment of malicious activities.
Excessive Usage of NSLOOKUP App
The following analytic detects excessive usage of the nslookup application, which may indicate potential DNS exfiltration attempts. It leverages Sysmon EventCode 1 to monitor process executions, specifically focusing on nslookup.exe. The detection identifies outliers by comparing the frequency of nslookup executions against a calculated threshold. This activity is significant as it can reveal attempts by malware or APT groups to exfiltrate data via DNS queries. If confirmed malicious, this behavior could allow attackers to stealthily transfer sensitive information out of the network, bypassing traditional data exfiltration defenses.