Techniques
Sample rules
Windows AppCertDLL Modification Via Command Line
- source: splunk
- technicques:
- T1546.009
Description
This analytic detects attempts to modify AppCertDLL registry keys via some command line utility. Values under this key are used to specify DLLs loaded by the Windows Session Manager. Such modifications can be abused by attackers to load malicious code early in the system startup process, enabling persistent malware execution with high privileges. If confirmed malicious, this behavior may lead to system compromise, persistence, and the evasion of security controls.
Detection logic
| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
from datamodel=Endpoint.Processes where
Processes.process="*\\Control\\Session Manager\\AppCertDLLs*"
by Processes.process Processes.vendor_product Processes.user_id
Processes.process_hash Processes.parent_process_name
Processes.parent_process_exec Processes.action Processes.dest
Processes.process_current_directory Processes.process_path
Processes.process_integrity_level Processes.original_file_name
Processes.parent_process Processes.parent_process_path
Processes.parent_process_guid Processes.parent_process_id
Processes.process_guid Processes.process_id
Processes.user Processes.process_name
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_appcertdll_modification_via_command_line_filter`