Techniques › T1546 › T1546.017
T1546.017 Udev Rules
persistence · privilege escalation — Linux · attack.mitre.org · JSON
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MITRE detection strategy
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analytics
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Sigma rules tagged attack.t1546.017
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KEV CVEs mapped here
<p>Adversaries may maintain persistence through executing malicious content triggered using udev rules. Udev is the Linux kernel device manager that dynamically manages device nodes, handles access to pseudo-device files in the
/dev directory, and responds to hardware events, such as when external devices like hard drives or keyboards are plugged in or removed. Udev uses rule files with match keys to specify the conditions a hardware event must meet and action keys to define the actions that should follow. Root permissions are required to create, modify, or delete rule files located in /etc/udev/rules.d/, /run/udev/rules.d/, /usr/lib/udev/rules.d/, /usr/local/lib/udev/rules.d/, and /lib/udev/rules.d/. Rule priority is determined by both directory and by the digit prefix in the rule filename.</p><p>Adversaries may abuse the udev subsystem by adding or modifying rules in udev rule files to execute malicious content. For example, an adversary may configure a rule to execute their binary each time the pseudo-device file, such as /dev/random, is accessed by an application. Although udev is limited to running short tasks and is restricted by systemd-udevd's sandbox (blocking network and filesystem access), attackers may use scripting commands under the action key RUN+= to detach and run the malicious content’s process in the background to bypass these controls.</p>KEV CVEs mapped to this technique · CTID Mappings Explorer
None. No KEV entry in the public mapping names this technique. Given that 74.7% of KEV has no mapping at all, this says more about the mapping than about the technique.
Detection strategy · ATT&CK Enterprise v19.2
- DET0375 Detection Strategy for T1546.017 - Udev Rules (Linux) v1.0
AN1056 LinuxMonitor for creation or modification of udev rules files in key directories (/etc/udev/rules.d/, /lib/udev/rules.d/, /usr/lib/udev/rules.d/). Look for RUN+= or IMPORT keys invoking suspicious binaries or scripts. Correlate this with process execution from systemd-udevd context, and file writes near udev reload/restart events. Combine this with unexpected background process spawning from udevd-related forks.Tunable:
UdevRulePathSuspiciousRunPatternTimeWindowParentProcess
Sigma rules · SigmaHQ da9bb07d64, tag attack.t1546.017
No Sigma rule carries this tag. MITRE publishes a detection strategy above, so the behaviour is specified; what is missing is public detection content.
Rules tagged at the parent level (attack.t1546) 10
These target the parent technique, not this sub-technique specifically. Listed for completeness, not counted as coverage.
Author: Omkar Gudhate
· 2020-09-27 (modified 2023-09-28) · logsource: product=windows category=registry_set · 07743f65-7ec9-404a-a519-913db7118a8d
Detects changes to 'HKCU\Software\Classes\Folder\shell\open\command\DelegateExecute'
Author: Kyaw Min Thein, Furkan Caliskan (@caliskanfurkan_)
· 2020-06-22 (modified 2023-10-11) · logsource: product=windows category=process_creation · 0ba863e6-def5-4e50-9cea-4dd8c7dc46a4
Detects the malicious use of a control panel item
Author: frack113
· 2022-04-23 · logsource: product=windows category=file_event · 0c3fac91-5627-46e8-a6a8-a0d7b9b8ae1b
Get-Variable is a valid PowerShell cmdlet
WindowsApps is by default in the path where PowerShell is executed.
So when the Get-Variable command is issued on PowerShell execution, the system first looks for the Get-Variable executable in the path and executes the malicious binary instead of looking for the PowerShell cmdlet.
Author: Nasreddine Bencherchali (Nextron Systems)
· 2023-02-08 · logsource: product=windows category=file_event · 117d3d3a-755c-4a61-b23e-9171146d094c
Detects the creation of a macro file for Outlook.
Author: Nasreddine Bencherchali (Nextron Systems)
· 2021-04-05 (modified 2023-08-17) · logsource: product=windows category=registry_set · 396ae3eb-4174-4b9b-880e-dc0364d78a19
Detects the modification of Outlook setting "LoadMacroProviderOnBoot" which if enabled allows the automatic loading of any configured VBA project/module
Author: Denis Szadkowski, DIRT / DCSO CyTec
· 2022-10-09 · logsource: product=windows service=application · 711ab2fe-c9ba-4746-8840-5228a58c3cb8
This rule detects the execution of the extended storage procedure backdoor named Maggie in the context of Microsoft SQL server
Author: MSTIC, FPT.EagleEye
· 2021-06-15 (modified 2022-10-09) · logsource: product=windows category=process_creation · 7ba08e95-1e0b-40cd-9db5-b980555e42fd
Suspicious behaviours related to an actor tracked by Microsoft as SOURGUM
Author: @ScoubiMtl
· 2021-04-05 (modified 2023-02-08) · logsource: product=windows category=file_event · 8c31f563-f9a7-450c-bfa8-35f8f32f1f61
Detects the creation of a macro file for Outlook.
Author: Florian Roth (Nextron Systems)
· 2021-03-09 (modified 2023-03-09) · logsource: product=windows category=process_creation · bbb2dedd-a0e3-46ab-ba6c-6c82ae7a9aa7
Detects activity observed by different researchers to be HAFNIUM group activity (or related) on Exchange servers
Author: @ScoubiMtl
· 2021-04-05 (modified 2023-08-17) · logsource: product=windows category=registry_set · e3b50fa5-3c3f-444e-937b-0a99d33731cd
Detects the modification of Outlook security setting to allow unprompted execution of macros.