LoFP LoFP / limited false positives should be present as installutil is not typically used to download remote files. filter as needed based on developers requirements.

Techniques

Sample rules

Windows InstallUtil URL in Command Line

Description

The following analytic detects the use of Windows InstallUtil.exe with an HTTP or HTTPS URL in the command line. This is identified through Endpoint Detection and Response (EDR) telemetry, focusing on command-line executions containing URLs. This activity is significant as it may indicate an attempt to download and execute malicious code, potentially bypassing application control mechanisms. If confirmed malicious, this could lead to unauthorized code execution, privilege escalation, or persistent access within the environment. Analysts should review the parent process, network connections, file modifications, and related processes for further investigation.

Detection logic


| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_installutil` Processes.process IN ("*http://*","*https://*") by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_installutil_url_in_command_line_filter`

Windows InstallUtil Uninstall Option with Network

Description

The following analytic identifies the use of Windows InstallUtil.exe making a remote network connection using the /u (uninstall) switch. This detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process and network activity data. This behavior is significant as it may indicate an attempt to download and execute code while bypassing application control mechanisms. If confirmed malicious, this activity could allow an attacker to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.

Detection logic


| tstats prestats=t `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where `process_installutil` Processes.process IN ("*/u*", "*uninstall*") by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product 
| `drop_dm_object_name(Processes)` 
| tstats prestats=t append=t `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Network_Traffic.All_Traffic where All_Traffic.dest_port!=0 by All_Traffic.action All_Traffic.app All_Traffic.dest All_Traffic.dest_ip All_Traffic.dest_port All_Traffic.direction All_Traffic.dvc All_Traffic.protocol All_Traffic.protocol_version All_Traffic.src All_Traffic.src_ip All_Traffic.src_port All_Traffic.transport All_Traffic.user All_Traffic.vendor_product All_Traffic.process_id 
| `drop_dm_object_name(All_Traffic)` 
| table action dest original_file_name parent_process parent_process_exec parent_process_guid parent_process_id parent_process_name parent_process_path process process_exec process_guid process_hash process_id process_integrity_level process_name process_path user user_id vendor_product app dest_ip dest_port direction dvc protocol protocol_version src src_ip src_port transport 
| stats values(action) as action values(dest) as dest values(original_file_name) as original_file_name values(parent_process) as parent_process values(parent_process_exec) as parent_process_exec values(parent_process_guid) as parent_process_guid values(parent_process_id) as parent_process_id values(parent_process_name) as parent_process_name values(parent_process_path) as parent_process_path values(process) as process values(process_exec) as process_exec values(process_hash) as process_hash values(process_guid) as process_guid values(process_integrity_level) as process_integrity_level values(process_name) as process_name values(process_path) as process_path values(user) as user values(user_id) as user_id values(vendor_product) as vendor_product values(app) as app values(dest_ip) as dest_ip values(dest_port) as dest_port values(direction) as direction values(dvc) as dvc values(protocol) as protocol values(protocol_version) as protocol_version values(src) as src values(src_ip) as src_ip values(src_port) as src_port values(transport) as transport by process_id 
| where isnotnull(process_name) AND isnotnull(dest_port) 
| `windows_installutil_uninstall_option_with_network_filter`

Windows InstallUtil Remote Network Connection

Description

The following analytic detects the Windows InstallUtil.exe binary making a remote network connection. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and network telemetry. This activity is significant because InstallUtil.exe can be exploited to download and execute malicious code, bypassing application control mechanisms. If confirmed malicious, an attacker could achieve code execution, potentially leading to further system compromise, data exfiltration, or lateral movement within the network. Analysts should review the parent process, network connections, and any associated file modifications to determine the legitimacy of this activity.

Detection logic


| tstats prestats=t `security_content_summariesonly` count FROM datamodel=Endpoint.Processes
  where `process_installutil`
  by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec 
  Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name 
  Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash 
  Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path 
  Processes.user Processes.user_id Processes.vendor_product 

| `drop_dm_object_name(Processes)` 

| tstats prestats=t append=t `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Network_Traffic.All_Traffic where All_Traffic.dest_port!=0
  by All_Traffic.action All_Traffic.app All_Traffic.dest All_Traffic.dest_ip All_Traffic.dest_port All_Traffic.direction 
  All_Traffic.dvc All_Traffic.protocol All_Traffic.protocol_version All_Traffic.src All_Traffic.src_ip All_Traffic.src_port 
  All_Traffic.transport All_Traffic.user All_Traffic.vendor_product All_Traffic.process_id

| `drop_dm_object_name(All_Traffic)` 

| table action dest original_file_name parent_process parent_process_exec 
  parent_process_guid parent_process_id parent_process_name 
  parent_process_path process process_exec process_guid process_hash 
  process_id process_integrity_level process_name process_path 
  user user_id vendor_product app dest_ip dest_port direction dvc protocol 
  protocol_version src src_ip src_port transport 

| stats values(action) as action values(dest) as dest values(original_file_name) as original_file_name values(parent_process) as parent_process 
  values(parent_process_exec) as parent_process_exec values(parent_process_guid) as parent_process_guid 
  values(parent_process_id) as parent_process_id values(parent_process_name) as parent_process_name 
  values(parent_process_path) as parent_process_path values(process) as process 
  values(process_exec) as process_exec values(process_hash) as process_hash 
  values(process_guid) as process_guid values(process_integrity_level) as process_integrity_level values(process_name) as process_name
  values(process_path) as process_path values(user) as user values(user_id) as user_id 
  values(vendor_product) as vendor_product values(app) as app values(dest_ip) as dest_ip values(dest_port) as dest_port values(direction) as direction
  values(dvc) as dvc values(protocol) as protocol values(protocol_version) as protocol_version values(src) as src values(src_ip) as src_ip values(src_port) as src_port values(transport) as transport by process_id 

| where isnotnull(process_name) AND isnotnull(dest_port) 

| `windows_installutil_remote_network_connection_filter`