Sigma Rules
921 rules found for "Microsoft"
Kapeka Backdoor Scheduled Task Creation
Detects Kapeka backdoor scheduled task creation based on attributes such as paths, commands line flags, etc.
Lummac Stealer Activity - Execution Of More.com And Vbc.exe
Detects the execution of more.com and vbc.exe in the process tree. This behavior was observed by a set of samples related to Lummac Stealer. The Lummac payload is injected into the vbc.exe process.
Potential Raspberry Robin Registry Set Internet Settings ZoneMap
Detects registry modifications related to the proxy configuration of the system, potentially associated with the Raspberry Robin malware, as seen in campaigns running in Q1 2024. Raspberry Robin may alter proxy settings to circumvent security measures, ensuring unhindered connection with Command and Control servers for maintaining control over compromised systems if there are any proxy settings that are blocking connections.
Forest Blizzard APT - File Creation Activity
Detects the creation of specific files inside of ProgramData directory. These files were seen being created by Forest Blizzard as described by MSFT.
Forest Blizzard APT - JavaScript Constrained File Creation
Detects the creation of JavaScript files inside of the DriverStore directory. Forest Blizzard used this to exploit the CVE-2022-38028 vulnerability in Windows Print Spooler service by modifying a JavaScript constraints file and executing it with SYSTEM-level permissions.
Forest Blizzard APT - Process Creation Activity
Detects the execution of specific processes and command line combination. These were seen being created by Forest Blizzard as described by MSFT.
Forest Blizzard APT - Custom Protocol Handler Creation
Detects the setting of a custom protocol handler with the name "rogue". Seen being created by Forest Blizzard APT as reported by MSFT.
Forest Blizzard APT - Custom Protocol Handler DLL Registry Set
Detects the setting of the DLL that handles the custom protocol handler. Seen being created by Forest Blizzard APT as reported by MSFT.
Potential Exploitation of GoAnywhere MFT Vulnerability
Detects suspicious command execution by child processes of the GoAnywhere Managed File Transfer (MFT) application, which may indicate exploitation such as CVE-2025-10035. This behavior is indicative of post-exploitation activity related to CVE-2025-10035, as observed in campaigns by the threat actor Storm-1175.
Suspicious Creation of .library-ms File — Potential CVE-2025-24054 Exploit
Detects creation of '.library-ms' files, which may indicate exploitation of CVE-2025-24054. This vulnerability allows an attacker to trigger an automatic outbound SMB or WebDAV authentication request to a remote server upon archive extraction. If the system is unpatched, no user interaction is required beyond extracting a malicious archive—potentially exposing the user's NTLMv2-SSP hash to the attacker.
Potential Exploitation of RCE Vulnerability CVE-2025-33053 - Image Load
Detects potential exploitation of remote code execution vulnerability CVE-2025-33053 by monitoring suspicious image loads from WebDAV paths. The exploit involves malicious executables from attacker-controlled WebDAV servers loading the Windows system DLLs like gdi32.dll, netapi32.dll, etc.
Potential Exploitation of RCE Vulnerability CVE-2025-33053 - Process Access
Detects potential exploitation of remote code execution vulnerability CVE-2025-33053 by looking for process access that involves legitimate Windows executables (iediagcmd.exe, CustomShellHost.exe) accessing suspicious executables hosted on WebDAV shares. This indicates an attacker may be exploiting Process.Start() search order manipulation to execute malicious code from attacker-controlled WebDAV servers instead of legitimate system binaries. The vulnerability allows unauthorized code execution through external control of file names or paths via WebDAV.
Potential Exploitation of RCE Vulnerability CVE-2025-33053
Detects potential exploitation of remote code execution vulnerability CVE-2025-33053 which involves unauthorized code execution via WebDAV through external control of file names or paths. The exploit abuses legitimate utilities like iediagcmd.exe or CustomShellHost.exe by manipulating their working directories to point to attacker-controlled WebDAV servers, causing them to execute malicious executables (like route.exe) from the WebDAV path instead of legitimate system binaries through Process.Start() search order manipulation.
Suspicious Child Process of SolarWinds WebHelpDesk
Detects suspicious child processes spawned by SolarWinds WebHelpDesk (WHD) application, which may indicate exploitation activity leveraging RCE vulnerabilities such as CVE-2025-40551, CVE-2025-40536, or CVE-2025-26399
Potential SharePoint ToolShell CVE-2025-53770 Exploitation - File Create
Detects the creation of file such as spinstall0.aspx which may indicate successful exploitation of CVE-2025-53770. CVE-2025-53770 is a zero-day vulnerability in SharePoint that allows remote code execution.
Potential SharePoint ToolShell CVE-2025-53770 Exploitation Indicators
Detects potential exploitation of CVE-2025-53770 by identifying indicators such as suspicious command lines discovered in Post-Exploitation activities. CVE-2025-53770 is a zero-day vulnerability in SharePoint that allows remote code execution.
SharePoint ToolShell CVE-2025-53770 Exploitation - Web IIS
Detects access to vulnerable SharePoint components potentially being exploited in CVE-2025-53770 through IIS web server logs. CVE-2025-53770 is a zero-day vulnerability in SharePoint that allows remote code execution.
Exploitation Activity of CVE-2025-59287 - WSUS Suspicious Child Process
Detects the creation of command-line interpreters (cmd.exe, powershell.exe) as child processes of Windows Server Update Services (WSUS) related process wsusservice.exe. This behavior is a key indicator of exploitation for the critical remote code execution vulnerability such as CVE-2025-59287, where attackers spawn shells to conduct reconnaissance and further post-exploitation activities.
Kalambur Backdoor Curl TOR SOCKS Proxy Execution
Detects the execution of the "curl.exe" command, referencing "SOCKS" and ".onion" domains, which could be indicative of Kalambur backdoor activity.
Mail Forwarding/Redirecting Activity In O365
Detects email forwarding or redirecting activity in O365 Audit logs.
Inbox Rules Creation Or Update Activity in O365
Detects inbox rule creation or update via O365 Audit logs, a technique commonly observed in Business Email Compromise (BEC) attacks to hide emails. The usage of inbox rules can be a sign of a compromised mailbox, where an attacker is attempting to evade detections by suppressing or redirecting incoming emails. Analysts should review these rules in context, validate whether they reflect normal user behavior, and correlate with other indicators such as unusual login activity or recent mailbox rule modifications.
Successful MSIX/AppX Package Installation
Detects successful MSIX/AppX package installations on Windows systems by monitoring EventID 854 in the Microsoft-Windows-AppXDeployment-Server/Operational log. While most installations are legitimate, this can help identify unauthorized or suspicious package installations. It is crucial to monitor such events as threat actors may exploit MSIX/AppX packages to deliver and execute malicious payloads.
Firewall Rule Modified In The Windows Firewall Exception List
Detects when a rule has been modified in the Windows firewall exception list
Scheduled Task Deletion
Detects scheduled task deletion events. Scheduled tasks are likely to be deleted if not used for persistence. Malicious Software often creates tasks directly under the root node e.g. \TASKNAME
ADS Zone.Identifier Deleted
Detects the deletion of the "Zone.Identifier" ADS. Attackers can leverage this in order to bypass security restrictions that make use of the ADS such as Microsoft Office apps.
DMP/HDMP File Creation
Detects the creation of a file with the ".dmp"/".hdmp" extension. Often created by software during a crash. Memory dumps can sometimes contain sensitive information such as credentials. It's best to determine the source of the crash.
Dbghelp/Dbgcore DLL Loaded By Uncommon/Suspicious Process
Detects the load of dbghelp/dbgcore DLL by a potentially uncommon or potentially suspicious process. The Dbghelp and Dbgcore DLLs export functions that allow for the dump of process memory. Tools like ProcessHacker, Task Manager and some attacker tradecraft use the MiniDumpWriteDump API found in dbghelp.dll or dbgcore.dll. As an example, SilentTrynity C2 Framework has a module that leverages this API to dump the contents of Lsass.exe and transfer it over the network back to the attacker's machine. Keep in mind that many legitimate Windows processes and services might load the aforementioned DLLs for debugging or other related purposes. Investigate the CommandLine and the Image location of the process loading the DLL.
Microsoft Excel Add-In Loaded
Detects Microsoft Excel loading an Add-In (.xll) file
Microsoft Word Add-In Loaded
Detects Microsoft Word loading an Add-In (.wll) file which can be used by threat actors for initial access or persistence.
Dllhost.EXE Initiated Network Connection To Non-Local IP Address
Detects Dllhost.EXE initiating a network connection to a non-local IP address. Aside from Microsoft own IP range that needs to be excluded. Network communication from Dllhost will depend entirely on the hosted DLL. An initial baseline is recommended before deployment.
Msiexec.EXE Initiated Network Connection Over HTTP
Detects a network connection initiated by an "Msiexec.exe" process over port 80 or 443. Adversaries might abuse "msiexec.exe" to install and execute remotely hosted packages. Use this rule to hunt for potentially anomalous or suspicious communications.
bXOR Operator Usage In PowerShell Command Line - PowerShell Classic
Detects powershell execution with that make use of to the bxor (Bitwise XOR). Attackers might use as an alternative obfuscation method to Base64 encoded commands. Investigate the CommandLine and process tree to determine if the activity is malicious.
Local Firewall Rules Enumeration Via NetFirewallRule Cmdlet
Detects execution of "Get-NetFirewallRule" or "Show-NetFirewallRule" to enumerate the local firewall rules on a host.
Inbox Rules Creation Or Update Activity Via ExchangePowerShell Cmdlet
Detects inbox rule creation or update via ExchangePowerShell cmdlet, a technique commonly observed in Business Email Compromise (BEC) attacks to hide emails. The usage of inbox rules can be a sign of a compromised mailbox, where an attacker is attempting to evade detections by suppressing or redirecting incoming emails. Analysts should review these rules in context, validate whether they reflect normal user behavior, and correlate with other indicators such as unusual login activity or recent mailbox rule modifications.
SMB over QUIC Via PowerShell Script
Detects the mounting of Windows SMB shares over QUIC, which can be an unexpected event in some enterprise environments
Use Of Remove-Item to Delete File - ScriptBlock
PowerShell Remove-Item with -Path to delete a file or a folder with "-Recurse"
Potential Data Exfiltration Over SMTP Via Send-MailMessage Cmdlet
Detects the execution of a PowerShell script with a call to the "Send-MailMessage" cmdlet along with the "-Attachments" flag. This could be a potential sign of data exfiltration via Email. Adversaries may steal data by exfiltrating it over an un-encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.
LSASS Access From Program In Potentially Suspicious Folder
Detects process access to LSASS memory with suspicious access flags and from a potentially suspicious folder
Uncommon GrantedAccess Flags On LSASS
Detects process access to LSASS memory with uncommon access flags 0x410 and 0x01410
Set Files as System Files Using Attrib.EXE
Detects the execution of "attrib" with the "+s" flag to mark files as system files
Potential File Override/Append Via SET Command
Detects the use of the "SET" internal command of Cmd.EXE with the /p flag followed directly by an "=" sign. Attackers used this technique along with an append redirection operator ">>" in order to update the content of a file indirectly. Ex: cmd /c >> example.txt set /p="test data". This will append "test data" to contents of "example.txt". The typical use case of the "set /p=" command is to prompt the user for input.
Diskshadow Child Process Spawned
Detects any child process spawning from "Diskshadow.exe". This could be due to executing Diskshadow in interpreter mode or script mode and using the "exec" flag to launch other applications.
Diskshadow Script Mode Execution
Detects execution of "Diskshadow.exe" in script mode using the "/s" flag. Attackers often abuse "diskshadow" to execute scripts that deleted the shadow copies on the systems. Investigate the content of the scripts and its location.
Potential DLL Sideloading Activity Via ExtExport.EXE
Detects the execution of "Extexport.exe".A utility that is part of the Internet Explorer browser and is used to export and import various settings and data, particularly when switching between Internet Explorer and other web browsers like Firefox. It allows users to transfer bookmarks, browsing history, and other preferences from Internet Explorer to Firefox or vice versa. It can be abused as a tool to side load any DLL. If a folder is provided in the command line it'll load any DLL with one of the following names "mozcrt19.dll", "mozsqlite3.dll", or "sqlite.dll". Arbitrary DLLs can also be loaded if a specific number of flags was provided.
Microsoft Workflow Compiler Execution
Detects the execution of Microsoft Workflow Compiler, which may permit the execution of arbitrary unsigned code.
CodePage Modification Via MODE.COM
Detects a CodePage modification using the "mode.com" utility. This behavior has been used by threat actors behind Dharma ransomware.
Suspicious New Instance Of An Office COM Object
Detects an svchost process spawning an instance of an office application. This happens when the initial word application creates an instance of one of the Office COM objects such as 'Word.Application', 'Excel.Application', etc. This can be used by malicious actors to create malicious Office documents with macros on the fly. (See vba2clr project in the references)
Invocation Of Crypto-Classes From The "Cryptography" PowerShell Namespace
Detects the invocation of PowerShell commands with references to classes from the "System.Security.Cryptography" namespace. The PowerShell namespace "System.Security.Cryptography" provides classes for on-the-fly encryption and decryption. These can be used for example in decrypting malicious payload for defense evasion.