Techniques › T1546 › T1546.005
T1546.005 Trap
privilege escalation · persistence — macOS, 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.t1546.005
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KEV CVEs mapped here
<p>Adversaries may establish persistence by executing malicious content triggered by an interrupt signal. The <code>trap</code> command allows programs and shells to specify commands that will be executed upon receiving interrupt signals. A common situation is a script allowing for graceful termination and handling of common keyboard interrupts like <code>ctrl+c</code> and <code>ctrl+d</code>.</p><p>Adversaries can use this to register code to be executed when the shell encounters specific interrupts as a persistence mechanism. Trap commands are of the following format <code>trap 'command list' signals</code> where "command list" will be executed when "signals" are received.</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
- DET0369 Detection Strategy for Event Triggered Execution via Trap (T1546.005) v1.0
AN1038 LinuxCorrelate file modifications in shell startup scripts (e.g., .bashrc, .profile) with embedded
trapcommands and observe if those changes are followed by the unexpected execution of child processes when terminal signals (e.g., SIGINT) are triggered. Use contextual linking with user session activity to detect privilege misuse.auditd:SYSCALLModification of user shell profile or trap registration via echo/redirection (e.g., echo "trap 'malicious_cmd' INT" >> ~/.bashrc)→ DC0061 File ModificationTunable:TargetShellFilePathSignalTrapNameTimeWindowAN1039 macOSDetect unauthorizedtrapcommand registrations in shell startup files (e.g., .zprofile, .bash_profile, .zshrc) followed by execution chains during user terminal interaction. Use Unified Logs and EDR telemetry to correlate shell command parsing and process tree anomalies.macos:unifiedlogCommand line containing `trap` or `echo 'trap` written to login shell files→ DC0032 Process Creationmacos:unifiedlogFile write or append to .zshrc, .bash_profile, .zprofile, etc.→ DC0061 File ModificationTunable:LoginShellConfigPathsTrapCommandLengthThresholdParentProcessAnomalyThreshold
Sigma rules · SigmaHQ da9bb07d64, tag attack.t1546.005
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.