EXPLORE DETECTIONS
Powershell Using memory As Backing Store
The following analytic detects suspicious PowerShell script execution using memory streams as a backing store, identified via EventCode 4104. It leverages PowerShell Script Block Logging to capture scripts that create new objects with memory streams, often used to decompress and execute payloads in memory. This activity is significant as it indicates potential in-memory execution of malicious code, bypassing traditional file-based detection. If confirmed malicious, this technique could allow attackers to execute arbitrary code, maintain persistence, or escalate privileges without leaving a trace on the disk.
PowerShell WebRequest Using Memory Stream
The following analytic detects the use of .NET classes in PowerShell to download a URL payload directly into memory, a common fileless malware staging technique. It leverages PowerShell Script Block Logging (EventCode=4104) to identify suspicious PowerShell commands involving `system.net.webclient`, `system.net.webrequest`, and `IO.MemoryStream`. This activity is significant as it indicates potential fileless malware execution, which is harder to detect and can bypass traditional file-based defenses. If confirmed malicious, this technique could allow attackers to execute code in memory, evade detection, and maintain persistence in the environment.
Powershell Windows Defender Exclusion Commands
The following analytic detects the use of PowerShell commands to add or set Windows Defender exclusions. It leverages EventCode 4104 to identify suspicious `Add-MpPreference` or `Set-MpPreference` commands with exclusion parameters. This activity is significant because adversaries often use it to bypass Windows Defender, allowing malicious code to execute without detection. If confirmed malicious, this behavior could enable attackers to evade antivirus defenses, maintain persistence, and execute further malicious activities undetected.
Prevent Automatic Repair Mode using Bcdedit
The following analytic detects the execution of "bcdedit.exe" with parameters to set the boot status policy to ignore all failures. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments. This activity is significant because it can indicate an attempt by ransomware to prevent a compromised machine from booting into automatic repair mode, thereby hindering recovery efforts. If confirmed malicious, this action could allow attackers to maintain control over the infected system, complicating remediation and potentially leading to further damage.
Print Processor Registry Autostart
The following analytic detects suspicious modifications or new entries in the Print Processor registry path. It leverages registry activity data from the Endpoint data model to identify changes in the specified registry path. This activity is significant because the Print Processor registry is known to be exploited by APT groups like Turla for persistence and privilege escalation. If confirmed malicious, this could allow an attacker to execute a malicious DLL payload by restarting the spoolsv.exe process, leading to potential control over the compromised machine.
Print Spooler Adding A Printer Driver
The following analytic detects the addition of new printer drivers by monitoring Windows PrintService operational logs, specifically EventCode 316. This detection leverages log data to identify messages indicating the addition or update of printer drivers, such as "kernelbase.dll" and "UNIDRV.DLL." This activity is significant as it may indicate exploitation attempts related to vulnerabilities like CVE-2021-34527 (PrintNightmare). If confirmed malicious, attackers could gain code execution or escalate privileges, potentially compromising the affected system. Immediate isolation and investigation of the endpoint are recommended.
Print Spooler Failed to Load a Plug-in
The following analytic detects driver load errors in the Windows PrintService Admin logs, specifically identifying issues related to CVE-2021-34527 (PrintNightmare). It triggers on error messages indicating the print spooler failed to load a plug-in module, such as "meterpreter.dll," with error code 0x45A. This detection method leverages specific event codes and error messages. This activity is significant as it may indicate an exploitation attempt of a known vulnerability. If confirmed malicious, an attacker could gain unauthorized code execution on the affected system, leading to potential system compromise.
Process Creating LNK file in Suspicious Location
The following analytic detects a process creating a `.lnk` file in suspicious locations such as `C:\User*` or `*\Local\Temp\*`. It leverages filesystem and process activity data from the Endpoint data model to identify this behavior. This activity can be significant because creating `.lnk` files in these directories is a common indicator of spear phishing tools to establish persistence or execute malicious payloads. If confirmed malicious, this could allow an attacker to maintain persistence, execute arbitrary code, or further compromise the system.
Process Deleting Its Process File Path
The following analytic identifies a process attempting to delete its own file path, a behavior often associated with defense evasion techniques. This detection leverages Sysmon EventCode 1 logs, focusing on command lines executed via cmd.exe that include deletion commands. This activity is significant as it may indicate malware, such as Clop ransomware, trying to evade detection by removing its executable file if certain conditions are met. If confirmed malicious, this could allow the attacker to persist undetected, complicating incident response and remediation efforts.
Process Execution via WMI
The following analytic detects the execution of a process by `WmiPrvSE.exe`, indicating potential use of WMI (Windows Management Instrumentation) for process creation. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and parent process relationships. This activity is significant as WMI can be used for lateral movement, remote code execution, or persistence by attackers. If confirmed malicious, this could allow an attacker to execute arbitrary commands or scripts, potentially leading to further compromise of the affected system or network.
Process Kill Base On File Path
The following analytic detects the use of `wmic.exe` with the `delete` command to remove an executable path. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, parent processes, and command-line executions. This activity is significant because it often indicates the initial stages of an adversary setting up malicious activities, such as cryptocurrency mining, on an endpoint. If confirmed malicious, this behavior could allow an attacker to disable security tools or other critical processes, facilitating further compromise and persistence within the environment.
Process Writing DynamicWrapperX
The following analytic detects a process writing the dynwrapx.dll file to disk and registering it in the registry. It leverages data from the Endpoint datamodel, specifically monitoring process and filesystem events. This activity is significant because DynamicWrapperX is an ActiveX component often used in scripts to call Windows API functions, and its presence in non-standard locations is highly suspicious. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the environment. Immediate investigation of parallel processes and registry modifications is recommended.
Processes launching netsh
The following analytic identifies processes launching netsh.exe, a command-line utility used to modify network configurations. It detects this activity by analyzing data from Endpoint Detection and Response (EDR) agents, focusing on process GUIDs, names, parent processes, and command-line executions. This behavior is significant because netsh.exe can be exploited to execute malicious helper DLLs, serving as a persistence mechanism. If confirmed malicious, an attacker could gain persistent access, modify network settings, and potentially escalate privileges, posing a severe threat to the network's integrity and security.
Processes Tapping Keyboard Events
The following analytic detects processes on macOS systems that are tapping keyboard events, potentially monitoring all keystrokes made by a user. It leverages data from osquery results within the Alerts data model, focusing on specific process names and command lines. This activity is significant as it is a common technique used by Remote Access Trojans (RATs) to log keystrokes, posing a serious security risk. If confirmed malicious, this could lead to unauthorized access to sensitive information, including passwords and personal data, compromising the integrity and confidentiality of the system.
Prohibited Network Traffic Allowed
The following analytic detects instances where network traffic, identified by port and transport layer protocol as prohibited in the "lookup_interesting_ports" table, is allowed. It uses the Network_Traffic data model to cross-reference traffic data against predefined security policies. This activity is significant for a SOC as it highlights potential misconfigurations or policy violations that could lead to unauthorized access or data exfiltration. If confirmed malicious, this could allow attackers to bypass network defenses, leading to potential data breaches and compromising the organization's security posture.
Protocol or Port Mismatch
The following analytic identifies network traffic where the higher layer protocol does not match the expected port, such as non-HTTP traffic on TCP port 80. It leverages data from network traffic inspection technologies like Bro or Palo Alto Networks firewalls. This activity is significant because it may indicate attempts to bypass firewall restrictions or conceal malicious communications. If confirmed malicious, this behavior could allow attackers to evade detection, maintain persistence, or exfiltrate data through commonly allowed ports, posing a significant threat to network security.
Protocols passing authentication in cleartext
The following analytic identifies the use of cleartext protocols that risk leaking sensitive information. It detects network traffic on legacy protocols such as Telnet (port 23), POP3 (port 110), IMAP (port 143), and non-anonymous FTP (port 21). The detection leverages the Network_Traffic data model to identify TCP traffic on these ports. Monitoring this activity is crucial as it can expose credentials and other sensitive data to interception. If confirmed malicious, attackers could capture authentication details, leading to unauthorized access and potential data breaches.
ProxyShell ProxyNotShell Behavior Detected
The following analytic identifies potential exploitation of Windows Exchange servers via ProxyShell or ProxyNotShell vulnerabilities, followed by post-exploitation activities such as running nltest, Cobalt Strike, Mimikatz, and adding new users. It leverages data from multiple analytic stories, requiring at least five distinct sources to trigger, thus reducing noise. This activity is significant as it indicates a high likelihood of an active compromise, potentially leading to unauthorized access, privilege escalation, and persistent threats within the environment. If confirmed malicious, attackers could gain control over the Exchange server, exfiltrate data, and maintain long-term access.
Randomly Generated Scheduled Task Name
The following analytic detects the creation of a Scheduled Task with a high entropy, randomly generated name, leveraging Event ID 4698. It uses the `ut_shannon` function from the URL ToolBox Splunk application to measure the entropy of the Task Name. This activity is significant as adversaries often use randomly named Scheduled Tasks for lateral movement and remote code execution, employing tools like Impacket or CrackMapExec. If confirmed malicious, this could allow attackers to execute arbitrary code remotely, potentially leading to further compromise and persistence within the network.
Randomly Generated Windows Service Name
The following analytic detects the installation of a Windows Service with a suspicious, high-entropy name, indicating potential malicious activity. It leverages Event ID 7045 and the `ut_shannon` function from the URL ToolBox Splunk application to identify services with random names. This behavior is significant as adversaries often use randomly named services for lateral movement and remote code execution. If confirmed malicious, this activity could allow attackers to execute arbitrary code, escalate privileges, or maintain persistence within the environment.
Ransomware Notes bulk creation
The following analytic identifies the bulk creation of ransomware notes (e.g., .txt, .html, .hta files) on an infected machine. It leverages Sysmon EventCode 11 to detect multiple instances of these file types being created within a short time frame. This activity is significant as it often indicates an active ransomware attack, where the attacker is notifying the victim of the encryption. If confirmed malicious, this behavior could lead to widespread data encryption, rendering critical files inaccessible and potentially causing significant operational disruption.
Recon AVProduct Through Pwh or WMI
The following analytic detects suspicious PowerShell script execution via EventCode 4104, specifically targeting checks for installed anti-virus products using WMI or PowerShell commands. This detection leverages PowerShell Script Block Logging to identify scripts containing keywords like "SELECT," "WMIC," "AntiVirusProduct," or "AntiSpywareProduct." This activity is significant as it is commonly used by malware and APT actors to map running security applications or services, potentially aiding in evasion techniques. If confirmed malicious, this could allow attackers to disable or bypass security measures, leading to further compromise of the endpoint.
Recon Using WMI Class
The following analytic detects suspicious PowerShell activity via EventCode 4104, where WMI performs event queries to gather information on running processes or services. This detection leverages PowerShell Script Block Logging to identify specific WMI queries targeting system information classes like Win32_Bios and Win32_OperatingSystem. This activity is significant as it often indicates reconnaissance efforts by an adversary to profile the compromised machine. If confirmed malicious, the attacker could gain detailed system information, aiding in further exploitation or lateral movement within the network.
Recursive Delete of Directory In Batch CMD
The following analytic detects the execution of a batch command designed to recursively delete files or directories, a technique often used by ransomware like Reddot to delete files in the recycle bin and prevent recovery. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that include specific flags for recursive and quiet deletions. This activity is significant as it indicates potential ransomware behavior aimed at data destruction. If confirmed malicious, it could lead to significant data loss and hinder recovery efforts, severely impacting business operations.