EXPLORE DETECTIONS
Windows Unusual Count Of Invalid Users Fail To Auth Using Kerberos
The following analytic identifies a source endpoint failing to authenticate with multiple invalid domain users using the Kerberos protocol. It leverages Event ID 4768, which is generated when the Key Distribution Center issues a Kerberos Ticket Granting Ticket (TGT) and detects failure code 0x6, indicating the user is not found in the Kerberos database. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges. If confirmed malicious, this activity could lead to unauthorized access and potential privilege escalation within the Active Directory environment.
Windows Unusual Count Of Invalid Users Failed To Auth Using NTLM
The following analytic identifies a source endpoint failing to authenticate with multiple invalid users using the NTLM protocol. It leverages EventCode 4776 and calculates the standard deviation for each host, using the 3-sigma rule to detect anomalies. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges. If confirmed malicious, this activity could lead to unauthorized access or privilege escalation, posing a significant threat to the Active Directory environment. This detection is focused on domain controllers.
Windows Unusual Count Of Users Fail To Auth Wth ExplicitCredentials
The following analytic identifies a source user failing to authenticate with multiple users using explicit credentials on a host. It leverages Windows Event Code 4648 and calculates the standard deviation for each host, using the 3-sigma rule to detect anomalies. This behavior is significant as it may indicate a Password Spraying attack, where an adversary attempts to gain initial access or elevate privileges. If confirmed malicious, this activity could lead to unauthorized access, privilege escalation, or further compromise of the Active Directory environment.
Windows Unusual Count Of Users Failed To Auth Using Kerberos
The following analytic identifies a source endpoint failing to authenticate multiple valid users using the Kerberos protocol, potentially indicating a Password Spraying attack. It leverages Event 4771, which is generated when the Key Distribution Center fails to issue a Kerberos Ticket Granting Ticket (TGT) due to a wrong password (failure code 0x18). This detection uses statistical analysis, specifically the 3-sigma rule, to identify unusual authentication failures. If confirmed malicious, this activity could allow an attacker to gain initial access or elevate privileges within an Active Directory environment.
Windows Unusual Count Of Users Failed To Authenticate From Process
The following analytic identifies a source process failing to authenticate multiple users, potentially indicating a Password Spraying attack. It leverages Windows Event 4625, which logs failed logon attempts, and uses statistical analysis to detect anomalies. This activity is significant as it may represent an adversary attempting to gain initial access or elevate privileges within an Active Directory environment. If confirmed malicious, the attacker could compromise multiple accounts, leading to unauthorized access, data exfiltration, or further lateral movement within the network.
Windows Unusual Count Of Users Failed To Authenticate Using NTLM
The following analytic identifies a source endpoint failing to authenticate multiple valid users using the NTLM protocol, potentially indicating a Password Spraying attack. It leverages Event 4776 from Domain Controllers, calculating the standard deviation for each host and applying the 3-sigma rule to detect anomalies. This activity is significant as it may represent an adversary attempting to gain initial access or elevate privileges. If confirmed malicious, the attacker could compromise multiple accounts, leading to unauthorized access and potential lateral movement within the network.
Windows Unusual Count Of Users Remotely Failed To Auth From Host
The following analytic identifies a source host failing to authenticate against a remote host with multiple users, potentially indicating a Password Spraying attack. It leverages Windows Event 4625 (failed logon attempts) and Logon Type 3 (remote authentication) to detect this behavior. This activity is significant as it may represent an adversary attempting to gain initial access or elevate privileges within an Active Directory environment. If confirmed malicious, this could lead to unauthorized access, privilege escalation, and further compromise of the network.
Windows Unusual File Creation in Confluence Directory
Detects executable file formats being created within the Confluence main directory. This can be indicative of exploitation of the Confluence web services to stage malware. This won't catch adversaries who modify the output location outside the Confluence directory when exploiting.
Windows Unusual FileZilla XML Config Access
The following analytic identifies processes accessing FileZilla XML config files such as recentservers.xml and sitemanager.xml. It leverages Windows Security Event logs, specifically monitoring EventCode 4663, which tracks object access events. This activity is significant because it can indicate unauthorized access or manipulation of sensitive configuration files used by FileZilla, a popular FTP client. If confirmed malicious, this could lead to data exfiltration, credential theft, or further compromise of the system.
Windows Unusual Intelliform Storage Registry Access
The following analytic identifies processes accessing Intelliform Storage Registry keys used by Internet Explorer. It leverages Windows Security Event logs, specifically monitoring EventCode 4663, which tracks object access events. This activity is significant because it can indicate unauthorized access or manipulation of sensitive registry keys used for storing form data in Internet Explorer. If confirmed malicious, this could lead to data exfiltration, credential theft, or further compromise of the system.
Windows Unusual NTLM Authentication Destinations By Source
The following analytic detects when an unusual number NTLM authentications is attempted by the same source against multiple destinations. This activity generally results when an attacker attempts to brute force, password spray, or otherwise authenticate to a multiple domain joined Windows devices using an NTLM based process/attack. This same activity may also generate a large number of EventID 4776 events as well.
Windows Unusual NTLM Authentication Destinations By User
The following analytic detects when an unusual number of NTLM authentications is attempted by the same user account against multiple destinations. This activity generally results when an attacker attempts to brute force, password spray, or otherwise authenticate to numerous domain joined Windows devices using an NTLM based process/attack. This same activity may also generate a large number of EventID 4776 events as well.
Windows Unusual NTLM Authentication Users By Destination
The following analytic detects when a device is the target of numerous NTLM authentications using a null domain. This activity generally results when an attacker attempts to brute force, password spray, or otherwise authenticate to a domain joined Windows device from a non-domain device. This activity may also generate a large number of EventID 4776 events in tandem, however these events will not indicate the attacker or target device.
Windows Unusual NTLM Authentication Users By Source
The following analytic detects when an unusual number of NTLM authentications is attempted by the same source. This activity generally results when an attacker attempts to brute force, password spray, or otherwise authenticate to a domain joined Windows device using an NTLM based process/attack. This same activity may also generate a large number of EventID 4776 events in as well.
Windows Unusual Process Load Mozilla NSS-Mozglue Module
The following analytic identifies processes loading Mozilla NSS-Mozglue libraries such as mozglue.dll and nss3.dll. It leverages Sysmon Event logs, specifically monitoring EventCode 7, which tracks image loaded events. This activity is significant because it can indicate unauthorized access or manipulation of these libraries, which are commonly used by Mozilla applications like Firefox and Thunderbird. If confirmed malicious, this could lead to data exfiltration, credential theft, or further compromise of the system.
Windows Unusual SysWOW64 Process Run System32 Executable
The following analytic detects an unusual process execution pattern where a process running from C:\Windows\SysWOW64\ attempts to execute a binary from C:\Windows\System32\. In a typical Windows environment, 32-bit processes under SysWOW64 should primarily interact with 32-bit binaries within the same directory. However, an execution flow where a 32-bit process spawns a 64-bit binary from System32 can indicate potential process injection, privilege escalation, evasion techniques, or unauthorized execution hijacking.
Windows USBSTOR Registry Key Modification
This analytic is used to identify when a USB removable media device is attached to a Windows host. In this scenario we are querying the Endpoint Registry data model to look for modifications to the HKLM\System\CurrentControlSet\Enum\USBSTOR\ key. Adversaries and Insider Threats may use removable media devices for several malicious activities, including initial access, execution, and exfiltration.
Windows User Deletion Via Net
The following analytic detects the use of net.exe or net1.exe command-line to delete a user account on a system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and command-line execution logs. This activity is significant as it may indicate an attempt to impair user accounts or cover tracks during lateral movement. If confirmed malicious, this could lead to unauthorized access removal, disruption of legitimate user activities, or concealment of adversarial actions, complicating incident response and forensic investigations.
Windows User Disabled Via Net
The following analytic detects the use of the `net.exe` utility to disable a user account via the command line. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line arguments. This activity is significant as it may indicate an adversary's attempt to disrupt user availability, potentially as a precursor to further malicious actions. If confirmed malicious, this could lead to denial of service for legitimate users, aiding the attacker in maintaining control or covering their tracks.
Windows User Discovery Via Net
The following analytic detects the execution of `net.exe` or `net1.exe` with command-line arguments `user` or `users` to query local and domain accounts. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as it indicates potential reconnaissance efforts by adversaries to enumerate local and domain users, which is a common step in situational awareness and Active Directory discovery. If confirmed malicious, this behavior could lead to further attacks, including privilege escalation and lateral movement within the network.
Windows User Execution Malicious URL Shortcut File
The following analytic detects the creation URL shortcut files, often used by malware like CHAOS ransomware. It leverages the Endpoint.Filesystem datamodel to identify ".url" files created outside common directories, such as "Program Files". This activity can be significant as ".URL" files can be used as mean to trick the user into visiting certain websites unknowingly, or when placed in certain locations such as "\\AppData\\Roaming\\Microsoft\\Windows\\Start Menu\\Programs\\Startup\\", it may allow the execution of malicious code upon system reboot. If confirmed malicious, this could allow an attacker to achieve persistence and execute harmful payloads, potentially leading to further system compromise and data loss.
Windows Visual Basic Commandline Compiler DNSQuery
The following analytic detects instances where vbc.exe, the Visual Basic Command Line Compiler, initiates DNS queries. Normally, vbc.exe operates locally to compile Visual Basic code and does not require internet access or to perform DNS lookups. Therefore, any observed DNS activity originating from vbc.exe is highly suspicious and indicative of potential malicious activity. This behavior often suggests that a malicious payload is masquerading as the legitimate vbc.exe process to establish command-and-control (C2) communication, resolve domains for data exfiltration, or download additional stages of malware. Security teams should investigate the process's parent, command-line arguments, and the resolved domains for further indicators of compromise.
Windows VSSVC Process Accessing Defender Engine
Detects vssvc.exe opening a handle to MsMpEng.exe. In the RedSun exploit, VSS participates in the cloud-file restore race that directs WD to write through the NTFS junction. This handle acquisition is observed at the exact moment of exploitation. vssvc querying MsMpEng is not expected in normal operation.
Windows Vulnerable 3CX Software
The following analytic detects instances of the 3CXDesktopApp.exe with a FileVersion of 18.12.x, leveraging Sysmon logs. This detection focuses on identifying vulnerable versions 18.12.407 and 18.12.416 of the 3CX desktop app. Monitoring this activity is crucial as these specific versions have known vulnerabilities that could be exploited by attackers. If confirmed malicious, exploitation of this vulnerability could lead to unauthorized access, code execution, or further compromise of the affected system, posing significant security risks.