Sigma Rules
1,405 rules found for "Nextron Systems"
ETW Trace Evasion Activity
Detects command line activity that tries to clear or disable any ETW trace log which could be a sign of logging evasion.
Suspicious Eventlog Clearing or Configuration Change Activity
Detects the clearing or configuration tampering of EventLog using utilities such as "wevtutil", "powershell" and "wmic". This technique were seen used by threat actors and ransomware strains in order to evade defenses.
Potentially Suspicious EventLog Recon Activity Using Log Query Utilities
Detects execution of different log query utilities and commands to search and dump the content of specific event logs or look for specific event IDs. This technique is used by threat actors in order to extract sensitive information from events logs such as usernames, IP addresses, hostnames, etc.
Potentially Suspicious Execution From Parent Process In Public Folder
Detects a potentially suspicious execution of a parent process located in the "\Users\Public" folder executing a child process containing references to shell or scripting binaries and commandlines.
Process Execution From A Potentially Suspicious Folder
Detects a potentially suspicious execution from an uncommon folder.
Suspicious FileFix Execution Pattern
Detects suspicious FileFix execution patterns where users are tricked into running malicious commands through browser file upload dialog manipulation. This attack typically begins when users visit malicious websites impersonating legitimate services or news platforms, which may display fake CAPTCHA challenges or direct instructions to open file explorer and paste clipboard content. The clipboard content usually contains commands that download and execute malware, such as information stealing tools.
Suspicious Reconnaissance Activity Via GatherNetworkInfo.VBS
Detects execution of the built-in script located in "C:\Windows\System32\gatherNetworkInfo.vbs". Which can be used to gather information about the target machine
Potential Hidden Directory Creation Via NTFS INDEX_ALLOCATION Stream - CLI
Detects command line containing reference to the "::$index_allocation" stream, which can be used as a technique to prevent access to folders or files from tooling such as "explorer.exe" or "powershell.exe"
Execution Of Non-Existing File
Checks whether the image specified in a process creation event is not a full, absolute path (caused by process ghosting or other unorthodox methods to start a process)
Base64 MZ Header In CommandLine
Detects encoded base64 MZ header in the commandline
Potentially Suspicious Inline JavaScript Execution via NodeJS Binary
Detects potentially suspicious inline JavaScript execution using Node.js with specific keywords in the command line.
Potential WinAPI Calls Via CommandLine
Detects the use of WinAPI Functions via the commandline. As seen used by threat actors via the tool winapiexec
Potentially Suspicious JWT Token Search Via CLI
Detects potentially suspicious search for JWT tokens via CLI by looking for the string "eyJ0eX" or "eyJhbG". JWT tokens are often used for access-tokens across various applications and services like Microsoft 365, Azure, AWS, Google Cloud, and others. Threat actors may search for these tokens to steal them for lateral movement or privilege escalation.
Suspicious LNK Command-Line Padding with Whitespace Characters
Detects exploitation of LNK file command-line length discrepancy, where attackers hide malicious commands beyond the 260-character UI limit while the actual command-line argument field supports 4096 characters using whitespace padding (e.g., 0x20, 0x09-0x0D). Adversaries insert non-printable whitespace characters (e.g., Line Feed \x0A, Carriage Return \x0D) to pad the visible section of the LNK file, pushing malicious commands past the UI-visible boundary. The hidden payload, executed at runtime but invisible in Windows Explorer properties, enables stealthy execution and evasion—commonly used for social engineering attacks. This rule flags suspicious use of such padding observed in real-world attacks.
LSASS Dump Keyword In CommandLine
Detects the presence of the keywords "lsass" and ".dmp" in the commandline, which could indicate a potential attempt to dump or create a dump of the lsass process.
Potential File Download Via MS-AppInstaller Protocol Handler
Detects usage of the "ms-appinstaller" protocol handler via command line to potentially download arbitrary files via AppInstaller.EXE The downloaded files are temporarly stored in ":\Users\%username%\AppData\Local\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe\AC\INetCache\<RANDOM-8-CHAR-DIRECTORY>"
Potential Network Sniffing Activity Using Network Tools
Detects potential network sniffing via use of network tools such as "tshark", "windump". Network sniffing refers to using the network interface on a system to monitor or capture information sent over a wired or wireless connection. An adversary may place a network interface into promiscuous mode to passively access data in transit over the network, or use span ports to capture a larger amount of data.
Execution of Suspicious File Type Extension
Detects whether the image specified in a process creation event doesn't refer to an ".exe" (or other known executable extension) file. This can be caused by process ghosting or other unorthodox methods to start a process. This rule might require some initial baselining to align with some third party tooling in the user environment.
Suspicious Process Patterns NTDS.DIT Exfil
Detects suspicious process patterns used in NTDS.DIT exfiltration
Potentially Suspicious Call To Win32_NTEventlogFile Class
Detects usage of the WMI class "Win32_NTEventlogFile" in a potentially suspicious way (delete, backup, change permissions, etc.) from a PowerShell script
Use Short Name Path in Image
Detect use of the Windows 8.3 short name. Which could be used as a method to avoid Image detection
Use NTFS Short Name in Command Line
Detect use of the Windows 8.3 short name. Which could be used as a method to avoid command-line detection
Use NTFS Short Name in Image
Detect use of the Windows 8.3 short name. Which could be used as a method to avoid Image based detection
Obfuscated IP Download Activity
Detects use of an encoded/obfuscated version of an IP address (hex, octal...) in an URL combined with a download command
Obfuscated IP Via CLI
Detects usage of an encoded/obfuscated version of an IP address (hex, octal, etc.) via command line
Suspicious Process Parents
Detects suspicious parent processes that should not have any children or should only have a single possible child program
Potential PowerShell Execution Via DLL
Detects potential PowerShell execution from a DLL instead of the usual PowerShell process as seen used in PowerShdll. This detection assumes that PowerShell commands are passed via the CommandLine.
Private Keys Reconnaissance Via CommandLine Tools
Adversaries may search for private key certificate files on compromised systems for insecurely stored credential
Suspicious RunAs-Like Flag Combination
Detects suspicious command line flags that let the user set a target user and command as e.g. seen in PsExec-like tools
Suspicious Program Names
Detects suspicious patterns in program names or folders that are often found in malicious samples or hacktools
Suspicious Process Execution From Fake Recycle.Bin Folder
Detects process execution from a fake recycle bin folder, often used to avoid security solution.
Suspicious Redirection to Local Admin Share
Detects a suspicious output redirection to the local admins share, this technique is often found in malicious scripts or hacktool stagers
Registry Modification of MS-settings Protocol Handler
Detects registry modifications to the 'ms-settings' protocol handler, which is frequently targeted for UAC bypass or persistence. Attackers can modify this registry to execute malicious code with elevated privileges by hijacking the command execution path.
Potential Defense Evasion Via Right-to-Left Override
Detects the presence of the "u202+E" character, which causes a terminal, browser, or operating system to render text in a right-to-left sequence. This character is used as an obfuscation and masquerading techniques by adversaries to trick users into opening malicious files.
Script Interpreter Execution From Suspicious Folder
Detects a suspicious script execution in temporary folders or folders accessible by environment variables
Suspicious Script Execution From Temp Folder
Detects a suspicious script executions from temporary folder
Script Interpreter Spawning Credential Scanner - Windows
Detects a script interpreter process (like node.js or bun) spawning a known credential scanning tool (e.g., trufflehog, gitleaks). This behavior is indicative of an attempt to find and steal secrets, as seen in the "Shai-Hulud: The Second Coming" campaign.
Sensitive File Access Via Volume Shadow Copy Backup
Detects a command that accesses the VolumeShadowCopy in order to extract sensitive files such as the Security or SAM registry hives or the AD database (ntds.dit)
Suspicious New Service Creation
Detects creation of a new service via "sc" command or the powershell "new-service" cmdlet with suspicious binary paths
Suspicious Service Binary Directory
Detects a service binary running in a suspicious directory
Suspicious Windows Service Tampering
Detects the usage of binaries such as 'net', 'sc' or 'powershell' in order to stop, pause, disable or delete critical or important Windows services such as AV, Backup, etc. As seen being used in some ransomware scripts
Shadow Copies Deletion Using Operating Systems Utilities
Shadow Copies deletion using operating systems utilities
Windows Shell/Scripting Processes Spawning Suspicious Programs
Detects suspicious child processes of a Windows shell and scripting processes such as wscript, rundll32, powershell, mshta...etc.
Process Creation Using Sysnative Folder
Detects process creation events that use the Sysnative folder (common for CobaltStrike spawns)
System File Execution Location Anomaly
Detects the execution of a Windows system binary that is usually located in the system folder from an uncommon location.
Suspicious SYSTEM User Process Creation
Detects a suspicious process creation as SYSTEM user (suspicious program or command line parameter)
Suspicious Userinit Child Process
Detects a suspicious child process of userinit
Suspicious Velociraptor Child Process
Detects the suspicious use of the Velociraptor DFIR tool to execute other tools or download additional payloads, as seen in a campaign where it was abused for remote access and to stage further attacks.