Sigma Rules
1,585 rules found for "defense-evasion"
NET NGenAssemblyUsageLog Registry Key Tamper
Detects changes to the NGenAssemblyUsageLog registry key. .NET Usage Log output location can be controlled by setting the NGenAssemblyUsageLog CLR configuration knob in the Registry or by configuring an environment variable (as described in the next section). By simplify specifying an arbitrary value (e.g. fake output location or junk data) for the expected value, a Usage Log file for the .NET execution context will not be created.
Trust Access Disable For VBApplications
Detects registry changes to Microsoft Office "AccessVBOM" to a value of "1" which disables trust access for VBA on the victim machine and lets attackers execute malicious macros without any Microsoft Office warnings.
Microsoft Office Protected View Disabled
Detects changes to Microsoft Office protected view registry keys with which the attacker disables this feature.
Python Function Execution Security Warning Disabled In Excel - Registry
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.
Outlook EnableUnsafeClientMailRules Setting Enabled - Registry
Detects an attacker trying to enable the outlook security setting "EnableUnsafeClientMailRules" which allows outlook to run applications or execute macros
Macro Enabled In A Potentially Suspicious Document
Detects registry changes to Office trust records where the path is located in a potentially suspicious location
Uncommon Microsoft Office Trusted Location Added
Detects changes to registry keys related to "Trusted Location" of Microsoft Office where the path is set to something uncommon. Attackers might add additional trusted locations to avoid macro security restrictions.
Office Macros Warning Disabled
Detects registry changes to Microsoft Office "VBAWarning" to a value of "1" which enables the execution of all macros, whether signed or unsigned.
MaxMpxCt Registry Value Changed
Detects changes to the "MaxMpxCt" registry value. MaxMpxCt specifies the maximum outstanding network requests for the server per client, which is used when negotiating a Server Message Block (SMB) connection with a client. Note if the value is set beyond 125 older Windows 9x clients will fail to negotiate. Ransomware threat actors and operators (specifically BlackCat) were seen increasing this value in order to handle a higher volume of traffic.
Potential Persistence Via Custom Protocol Handler
Detects potential persistence activity via the registering of a new custom protocole handlers. While legitimate applications register protocole handlers often times during installation. And attacker can abuse this by setting a custom handler to be used as a persistence mechanism.
Potential Persistence Via Event Viewer Events.asp
Detects potential registry persistence technique using the Event Viewer "Events.asp" technique
Potential Persistence Via GlobalFlags
Detects registry persistence technique using the GlobalFlags and SilentProcessExit keys
Modification of IE Registry Settings
Detects modification of the registry settings used for Internet Explorer and other Windows components that use these settings. An attacker can abuse this registry key to add a domain to the trusted sites Zone or insert JavaScript for persistence
Potential Persistence Via Mpnotify
Detects when an attacker register a new SIP provider for persistence and defense evasion
Potential Persistence Via Outlook Home Page
Detects potential persistence activity via outlook home page. An attacker can set a home page to achieve code execution and persistence by editing the WebView registry keys.
Potential Persistence Via Outlook Today Page
Detects potential persistence activity via outlook today page. An attacker can set a custom page to execute arbitrary code and link to it via the registry values "URL" and "UserDefinedUrl".
Potential WerFault ReflectDebugger Registry Value Abuse
Detects potential WerFault "ReflectDebugger" registry value abuse for persistence.
Potential Attachment Manager Settings Associations Tamper
Detects tampering with attachment manager settings policies associations to lower the default file type risks (See reference for more information)
Potential Attachment Manager Settings Attachments Tamper
Detects tampering with attachment manager settings policies attachments (See reference for more information)
Registry Modification for OCI DLL Redirection
Detects registry modifications related to 'OracleOciLib' and 'OracleOciLibPath' under 'MSDTC' settings. Threat actors may modify these registry keys to redirect the loading of 'oci.dll' to a malicious DLL, facilitating phantom DLL hijacking via the MSDTC service.
Potential PowerShell Execution Policy Tampering
Detects changes to the PowerShell execution policy in order to bypass signing requirements for script execution
PowerShell Logging Disabled Via Registry Key Tampering
Detects changes to the registry for the currently logged-in user. In order to disable PowerShell module logging, script block logging or transcription and script execution logging
Potential Provisioning Registry Key Abuse For Binary Proxy Execution - REG
Detects potential abuse of the provisioning registry key for indirect command execution through "Provlaunch.exe".
ETW Logging Disabled For rpcrt4.dll
Detects changes to the "ExtErrorInformation" key in order to disable ETW logging for rpcrt4.dll
ScreenSaver Registry Key Set
Detects registry key established after masqueraded .scr file execution using Rundll32 through desk.cpl
ETW Logging Disabled For SCM
Detects changes to the "TracingDisabled" key in order to disable ETW logging for services.exe (SCM)
Registry Explorer Policy Modification
Detects registry modifications that disable internal tools or functions in explorer (malware like Agent Tesla uses this technique)
Persistence Via New SIP Provider
Detects when an attacker register a new SIP provider for persistence and defense evasion
Tamper With Sophos AV Registry Keys
Detects tamper attempts to sophos av functionality via registry key modification
Hiding User Account Via SpecialAccounts Registry Key
Detects modifications 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.
Activate Suppression of Windows Security Center Notifications
Detect set Notification_Suppress to 1 to disable the Windows security center notification
Potential PendingFileRenameOperations Tampering
Detect changes to the "PendingFileRenameOperations" registry key from uncommon or suspicious images locations to stage currently used files for rename or deletion after reboot.
Suspicious Printer Driver Empty Manufacturer
Detects a suspicious printer driver installation with an empty Manufacturer value
Suspicious Space Characters in RunMRU Registry Path - ClickFix
Detects the occurrence of numerous space characters in RunMRU registry paths, which may indicate execution via phishing lures using clickfix techniques to hide malicious commands in the Windows Run dialog box from naked eyes.
Suspicious Service Installed
Detects installation of NalDrv or PROCEXP152 services via registry-keys to non-system32 folders. Both services are used in the tool Ghost-In-The-Logs (https://github.com/bats3c/Ghost-In-The-Logs), which uses KDU (https://github.com/hfiref0x/KDU)
Suspicious Shell Open Command Registry Modification
Detects modifications to shell open registry keys that point to suspicious locations typically used by malware for persistence. Generally, modifications to the `*\shell\open\command` registry key can indicate an attempt to change the default action for opening files, and various UAC bypass or persistence techniques involve modifying these keys to execute malicious scripts or binaries.
Suspicious Space Characters in TypedPaths Registry Path - FileFix
Detects the occurrence of numerous space characters in TypedPaths registry paths, which may indicate execution via phishing lures using file-fix techniques to hide malicious commands.
WFP Filter Added via Registry
Detects registry modifications that add Windows Filtering Platform (WFP) filters, which may be used to block security tools and EDR agents from reporting events.
Suspicious Environment Variable Has Been Registered
Detects the creation of user-specific or system-wide environment variables via the registry. Which contains suspicious commands and strings
Enable LM Hash Storage
Detects changes to the "NoLMHash" registry value in order to allow Windows to store LM Hashes. By setting this registry value to "0" (DWORD), Windows will be allowed to store a LAN manager hash of your password in Active Directory and local SAM databases.
RDP Sensitive Settings Changed to Zero
Detects tampering of RDP Terminal Service/Server sensitive settings. Such as allowing unauthorized users access to a system via the 'fAllowUnsolicited' or enabling RDP via 'fDenyTSConnections', etc.
RDP Sensitive Settings Changed
Detects tampering of RDP Terminal Service/Server sensitive settings. Such as allowing unauthorized users access to a system via the 'fAllowUnsolicited' or enabling RDP via 'fDenyTSConnections', etc. Below is a list of registry keys/values that are monitored by this rule: - Shadow: Used to enable Remote Desktop shadowing, which allows an administrator to view or control a user's session. - DisableRemoteDesktopAntiAlias: Disables anti-aliasing for remote desktop sessions. - DisableSecuritySettings: Disables certain security settings for Remote Desktop connections. - fAllowUnsolicited: Allows unsolicited remote assistance offers. - fAllowUnsolicitedFullControl: Allows unsolicited remote assistance offers with full control. - InitialProgram: Specifies a program to run automatically when a user logs on to a remote computer. - ServiceDll: Used in RDP hijacking techniques to specify a custom DLL to be loaded by the Terminal Services service. - SecurityLayer: Specifies the security layer used for RDP connections.
Old TLS1.0/TLS1.1 Protocol Version Enabled
Detects applications or users re-enabling old TLS versions by setting the "Enabled" value to "1" for the "Protocols" registry key.
Potential Signing Bypass Via Windows Developer Features - Registry
Detects when the enablement of developer features such as "Developer Mode" or "Application Sideloading". Which allows the user to install untrusted packages.
UAC Bypass via Event Viewer
Detects UAC bypass method using Windows event viewer
UAC Bypass via Sdclt
Detects the pattern of UAC Bypass using registry key manipulation of sdclt.exe (e.g. UACMe 53)
UAC Bypass Abusing Winsat Path Parsing - Registry
Detects the pattern of UAC Bypass using a path parsing issue in winsat.exe (UACMe 52)
UAC Bypass Using Windows Media Player - Registry
Detects the pattern of UAC Bypass using Windows Media Player osksupport.dll (UACMe 32)