Windows Potential AppDomainManager Hijack Artifacts Creation
Description
The following analytic detects the creation of an .exe file along with its corresponding .exe.config and a .dll in the same directory, which is a common pattern indicative of potential AppDomain hijacking or CLR code injection attempts. This behavior may signal that a malicious actor is attempting to load a rogue assembly into a legitimate application's AppDomain, allowing code execution under the context of a trusted process.
Query · spl
| tstats `security_content_summariesonly` count min(_time) AS firstTime max(_time) AS lastTime from datamodel=Endpoint.Filesystem
where Filesystem.file_name IN ("*.exe", "*.exe.config", "*.dll") AND Filesystem.file_path IN
("*\\windows\\fonts\\*", "*\\temp\\*", "*\\users\\public\\*", "*\\windows\\debug\\*","*\\Users\\Administrator\\Music\\*", "*\\Windows\\servicing\\*", "*\\Users\\Default\\*", "*Recycle.bin*", "*\\Windows\\Media\\*", "*\\Windows\\repair\\*", "*\\PerfLogs\\*")
AND Filesystem.action = "created"
by Filesystem.action Filesystem.dest Filesystem.file_access_time Filesystem.file_create_time Filesystem.file_hash Filesystem.file_modify_time Filesystem.file_name Filesystem.file_path Filesystem.file_acl Filesystem.file_size Filesystem.process_guid Filesystem.process_id Filesystem.user Filesystem.vendor_product
| `drop_dm_object_name("Filesystem")`
| stats values(file_name) AS file_name
values(file_path) AS file_path
values(user) AS user
min(firstTime) AS firstTime max(lastTime) AS lastTime
BY dest process_guid
| eval exe_present = if(mvcount(mvfilter(match(file_name, "\.exe$"))) > 0, 1, 0)
| eval config_present = if(mvcount(mvfilter(match(file_name, "\.exe\.config$"))) > 0, 1, 0)
| eval dll_present = if(mvcount(mvfilter(match(file_name, "\.dll$"))) > 0, 1, 0)
| eval exe_files = mvfilter(match(file_name, "\.exe$") AND NOT match(file_name, "\.exe\.config$"))
| eval config_files = mvfilter(match(file_name, "\.exe\.config$"))
| eval exe_base_names = mvmap(exe_files, replace(exe_files, "\.exe$", ""))
| eval config_base_names = mvmap(config_files, replace(config_files, "\.exe\.config$", ""))
| mvexpand exe_base_names
| mvexpand config_base_names
| eval file_count = mvcount(file_name)
| where file_count >= 3 AND exe_present = 1 AND config_present = 1 AND dll_present = 1 AND exe_base_names = config_base_names
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_potential_appdomainmanager_hijack_artifacts_creation_filter`
Implementation guide
To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Filesystem node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
Known false positives
- This detection may still produce false positives, so additional filtering is recommended. To validate potential alerts, verify that the executable’s original file name matches its current file name, and also review the associated .config file to confirm which DLLs are expected to load during execution. This helps distinguish legitimate activity from suspicious behavior.
Analyst notes
Known false positives: This detection may still produce false positives, so additional filtering is recommended. To validate potential alerts, verify that the executable’s original file name matches its current file name, and also review the associated .config file to confirm which DLLs are expected to load during execution. This helps distinguish legitimate activity from suspicious behavior.