Sigma Rules
39 rules found for "kostastsale"
Suspicious Filename with Embedded Base64 Commands
Detects files with specially crafted filenames that embed Base64-encoded bash payloads designed to execute when processed by shell scripts. These filenames exploit shell interpretation quirks to trigger hidden commands, a technique observed in VShell malware campaigns.
Kerberoasting Activity - Initial Query
This rule will collect the data needed to start looking into possible kerberoasting activity. Further analysis or computation within the query is needed focusing on requests from one specific host/IP towards multiple service names within a time period of 5 seconds. You can then set a threshold for the number of requests and time between the requests to turn this into an alert.
Potentially Suspicious File Creation by OpenEDR's ITSMService
Detects the creation of potentially suspicious files by OpenEDR's ITSMService process. The ITSMService is responsible for remote management operations and can create files on the system through the Process Explorer or file management features. While legitimate for IT operations, creation of executable or script files could indicate unauthorized file uploads, data staging, or malicious file deployment.
Uncommon Connection to Active Directory Web Services
Detects uncommon network connections to the Active Directory Web Services (ADWS) from processes not typically associated with ADWS management.
OpenEDR Spawning Command Shell
Detects the OpenEDR ssh-shellhost.exe spawning a command shell (cmd.exe) or PowerShell with PTY (pseudo-terminal) capabilities. This may indicate remote command execution through OpenEDR's remote management features, which could be legitimate administrative activity or potential abuse of the remote access tool. Threat actors may leverage OpenEDR's remote shell capabilities to execute commands on compromised systems, facilitating lateral movement or other command-and-control operations.
File Explorer Folder Opened Using Explorer Folder Shortcut Via Shell
Detects the initial execution of "cmd.exe" which spawns "explorer.exe" with the appropriate command line arguments for opening the "My Computer" folder.
HackTool - SharpWSUS/WSUSpendu Execution
Detects the execution of SharpWSUS or WSUSpendu, utilities that allow for lateral movement through WSUS. Windows Server Update Services (WSUS) is a critical component of Windows systems and is frequently configured in a way that allows an attacker to circumvent internal networking limitations.
HackTool - SOAPHound Execution
Detects the execution of SOAPHound, a .NET tool for collecting Active Directory data, using specific command-line arguments that may indicate an attempt to extract sensitive AD information.
OneNote.EXE Execution of Malicious Embedded Scripts
Detects the execution of malicious OneNote documents that contain embedded scripts. When a user clicks on a OneNote attachment and then on the malicious link inside the ".one" file, it exports and executes the malicious embedded script from specific directories.
Obfuscated PowerShell OneLiner Execution
Detects the execution of a specific OneLiner to download and execute powershell modules in memory.
Python Function Execution Security Warning Disabled In Excel
Detects changes to the registry value "PythonFunctionWarnings" that would prevent any warnings or alerts from showing when Python functions are about to be executed. Threat actors could run malicious code through the new Microsoft Excel feature that allows Python to run within the spreadsheet.
Hiding User Account Via SpecialAccounts Registry Key - CommandLine
Detects changes to the registry key "HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\Userlist" where the value is set to "0" in order to hide user account from being listed on the logon screen.
Remote Access Tool - MeshAgent Command Execution via MeshCentral
Detects the use of MeshAgent to execute commands on the target host, particularly when threat actors might abuse it to execute commands directly. MeshAgent can execute commands on the target host by leveraging win-console to obscure their activities and win-dispatcher to run malicious code through IPC with child processes.
Renamed CURL.EXE Execution
Detects the execution of a renamed "CURL.exe" binary based on the PE metadata fields
Potentially Suspicious Rundll32.EXE Execution of UDL File
Detects the execution of rundll32.exe with the oledb32.dll library to open a UDL file. Threat actors can abuse this technique as a phishing vector to capture authentication credentials or other sensitive data.
Sdiagnhost Calling Suspicious Child Process
Detects sdiagnhost.exe calling a suspicious child process (e.g. used in exploits for Follina / CVE-2022-30190)
Potential Defense Evasion Activity Via Emoji Usage In CommandLine - 1
Detects the usage of emojis in the command line, this could be a sign of potential defense evasion activity.
Potential Defense Evasion Activity Via Emoji Usage In CommandLine - 2
Detects the usage of emojis in the command line, this could be a sign of potential defense evasion activity.
Potential Defense Evasion Activity Via Emoji Usage In CommandLine - 3
Detects the usage of emojis in the command line, this could be a sign of potential defense evasion activity.
Potential Defense Evasion Activity Via Emoji Usage In CommandLine - 4
Detects the usage of emojis in the command line, this could be a sign of potential defense evasion activity.
Antivirus Filter Driver Disallowed On Dev Drive - Registry
Detects activity that indicates a user disabling the ability for Antivirus mini filter to inspect a "Dev Drive".
Exploitation Attempt Of CVE-2020-1472 - Execution of ZeroLogon PoC
Detects the execution of the commonly used ZeroLogon PoC executable.
Potential CVE-2021-44228 Exploitation Attempt - VMware Horizon
Detects potential initial exploitation attempts against VMware Horizon deployments running a vulnerable versions of Log4j.
Potential CVE-2022-22954 Exploitation Attempt - VMware Workspace ONE Access Remote Code Execution
Detects potential exploitation attempt of CVE-2022-22954, a remote code execution vulnerability in VMware Workspace ONE Access and Identity Manager. As reported by Morphisec, part of the attack chain, threat actors used PowerShell commands that executed as a child processes of the legitimate Tomcat "prunsrv.exe" process application.
ChromeLoader Malware Execution
Detects execution of ChromeLoader malware via a registered scheduled task
Emotet Loader Execution Via .LNK File
Detects the Emotet Epoch4 loader as reported by @malware_traffic back in 2022. The ".lnk" file was delivered via phishing campaign.
Raspberry Robin Subsequent Execution of Commands
Detects raspberry robin subsequent execution of commands.
Raspberry Robin Initial Execution From External Drive
Detects the initial execution of the Raspberry Robin malware from an external drive using "Cmd.EXE".
Serpent Backdoor Payload Execution Via Scheduled Task
Detects post exploitation execution technique of the Serpent backdoor. According to Proofpoint, one of the commands that the backdoor ran was via creating a temporary scheduled task using an unusual method. It creates a fictitious windows event and a trigger in which once the event is created, it executes the payload.
FakeUpdates/SocGholish Activity
Detects initial execution of FakeUpdates/SocGholish malware via wscript that later executes commands via cmd or powershell.
Potential MOVEit Transfer CVE-2023-34362 Exploitation - Dynamic Compilation Via Csc.EXE
Detects the execution of "csc.exe" via "w3wp.exe" process. MOVEit affected hosts execute "csc.exe" via the "w3wp.exe" process to dynamically compile malicious DLL files. MOVEit is affected by a critical vulnerability. Exploited hosts show evidence of dynamically compiling a DLL and writing it under C:\\Windows\\Microsoft\.NET\\Framework64\\v4\.0\.30319\\Temporary ASP\.NET Files\\root\\([a-z0-9]{5,12})\\([a-z0-9]{5,12})\\App_Web_[a-z0-9]{5,12}\.dll. Hunting Opportunity Events from IIS dynamically compiling binaries via the csc.exe on behalf of the MOVEit application, especially since May 27th should be investigated.
Injected Browser Process Spawning Rundll32 - GuLoader Activity
Detects the execution of installed GuLoader malware on the host. GuLoader is initiating network connections via the rundll32.exe process that is spawned via a browser parent(injected) process.
Ursnif Redirection Of Discovery Commands
Detects the redirection of Ursnif discovery commands as part of the initial execution of the malware.
Potentially Suspicious Long Filename Pattern - Linux
Detects the creation of files with unusually long filenames (100 or more characters), which may indicate obfuscation techniques used by malware such as VShell. This is a hunting rule to identify potential threats that use long filenames to evade detection. Keep in mind that on a legitimate system, such long filenames can and are common. Run this detection in the context of threat hunting rather than alerting. Adjust the threshold of filename length as needed based on your environment.
Remote Access Tool - Action1 Arbitrary Code Execution and Remote Sessions
Detects the execution of Action1 in order to execute arbitrary code or establish a remote session. Action1 is a powerful Remote Monitoring and Management tool that enables users to execute commands, scripts, and binaries. Through the web interface of action1, the administrator must create a new policy or an app to establish remote execution and then points that the agent is installed. Hunting Opportunity 1- Weed Out The Noise When threat actors execute a script, a command, or a binary through these new policies and apps, the names of these become visible in the command line during the execution process. Below is an example of the command line that contains the deployment of a binary through a policy with name "test_app_1": ParentCommandLine: "C:\WINDOWS\Action1\action1_agent.exe schedule:Deploy_App__test_app_1_1681327673425 runaction:0" After establishing a baseline, we can split the command to extract the policy name and group all the policy names and inspect the results with a list of frequency occurrences. Hunting Opportunity 2 - Remote Sessions On Out Of Office Hours If you have admins within your environment using remote sessions to administer endpoints, you can create a threat-hunting query and modify the time of the initiated sessions looking for abnormal activity.
Remote Access Tool - Ammy Admin Agent Execution
Detects the execution of the Ammy Admin RMM agent for remote management.
Remote Access Tool - Cmd.EXE Execution via AnyViewer
Detects execution of "cmd.exe" via the AnyViewer RMM agent on a remote management sessions.
Potential Suspicious Execution From GUID Like Folder Names
Detects potential suspicious execution of a GUID like folder name located in a suspicious location such as %TEMP% as seen being used in IcedID attacks. Use this rule to hunt for potentially suspicious activity stemming from uncommon folders.
Manual Execution of Script Inside of a Compressed File
This is a threat-hunting query to collect information related to the interactive execution of a script from inside a compressed file (zip/rar). Windows will automatically run the script using scripting interpreters such as wscript and cscript binaries. From the query below, the child process is the script interpreter that will execute the script. The script extension is also a set of standard extensions that Windows OS recognizes. Selections 1-3 contain three different execution scenarios. 1. Compressed file opened using 7zip. 2. Compressed file opened using WinRar. 3. Compressed file opened using native windows File Explorer capabilities. When the malicious script is double-clicked, it will be extracted to the respected directories as signified by the CommandLine on each of the three Selections. It will then be executed using the relevant script interpreter."