Detection rules › Splunk
Potential AutoHotkey .ahk Execution (Windows Event Log)
Adversaries may execute commands and perform malicious tasks using AutoIT and AutoHotKey automation scripts. AutoIT and AutoHotkey (AHK) are scripting languages that enable users to automate Windows tasks. These automation scripts can be used to perform a wide variety of actions, such as clicking on buttons, entering text, and opening and closing programs. This use case detects exeuction of .ahk files, accounting for renamed AutoHotkey binaries. Due to the broad nature of this rule, false positives for .ahk creation are expected. Allowlisting for expected executables and command line arguments is recommended.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1059 Command and Scripting Interpreter |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
id: '32266.57401'
title: Potential AutoHotkey .ahk Execution
description: Adversaries may execute commands and perform malicious tasks using AutoIT
and AutoHotKey automation scripts. AutoIT and AutoHotkey (AHK) are scripting languages
that enable users to automate Windows tasks. These automation scripts can be used
to perform a wide variety of actions, such as clicking on buttons, entering text,
and opening and closing programs. This use case detects exeuction of .ahk files,
accounting for renamed AutoHotkey binaries. Due to the broad nature of this rule,
false positives for .ahk creation are expected. Allowlisting for expected executables
and command line arguments is recommended.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
"<EventID>4688<" OR Type=Process) ".ahk" | regex process="(?i)\.exe.+\S+\.ahk(\s|$|\")"
| table _time, host, user, process, parent_process_name, process_name, process_path
| bin span=1s | stats values(*) as * by _time, host '
techniques:
- execution:command and scripting interpreter
technique_id:
- T1059
data_category:
- Process command-line parameters
- Windows event logs
references:
- https://attack.mitre.org/techniques/T1059/010/
- https://detection.fyi/sigmahq/sigma/windows/process_creation/proc_creation_win_renamed_autohotkey/
- https://www.autohotkey.com/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR "<EventID>4688<" OR Type=Process) ".ahk"
Stage 2: regex
| regex process="(?i)\.exe.+\S+\.ahk(\s|$|\")"
Stage 3: table
| table _time, host, user, process, parent_process_name, process_name, process_path
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
Search terms
Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.
| Stage | Term |
|---|---|
| 1 | TERM |
| 1 | "<EventID>4688<" |
| 1 | ".ahk" |