Techniques
Sample rules
Suspicious SearchProtocolHost no Command Line Arguments
- source: splunk
- technicques:
- T1055
Description
The following analytic detects instances of searchprotocolhost.exe running without command line arguments. This behavior is unusual and often associated with malicious activities, such as those performed by Cobalt Strike. The detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process execution data. This activity is significant because searchprotocolhost.exe typically runs with specific arguments, and its absence may indicate an attempt to evade detection. If confirmed malicious, this could lead to unauthorized code execution, potential credential dumping, or other malicious actions within the environment.
Detection logic
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where Processes.process_name=searchprotocolhost.exe 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)`
| regex process="(?i)(searchprotocolhost\.exe.{0,4}$)"
| `suspicious_searchprotocolhost_no_command_line_arguments_filter`
SearchProtocolHost with no Command Line with Network
- source: splunk
- technicques:
- T1055
Description
The following analytic detects instances of searchprotocolhost.exe running without command line arguments but with an active network connection. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process execution and network traffic data. It is significant because searchprotocolhost.exe typically runs with specific command line arguments, and deviations from this norm can indicate malicious activity, such as Cobalt Strike usage. If confirmed malicious, this activity could allow attackers to establish network connections for command and control, potentially leading to data exfiltration or further system compromise.
Detection logic
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where Processes.process_name=searchprotocolhost.exe by _time span=1h Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| regex process="(?i)(searchprotocolhost\.exe.{0,4}$)"
| join process_id [
| tstats `security_content_summariesonly` count FROM datamodel=Network_Traffic.All_Traffic where All_Traffic.dest_port != 0 by All_Traffic.action All_Traffic.app All_Traffic.bytes All_Traffic.bytes_in All_Traffic.bytes_out All_Traffic.dest All_Traffic.dest_ip All_Traffic.dest_port 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.direction All_Traffic.process_id
| `drop_dm_object_name(All_Traffic)`
| rename dest as C2 ]
| table _time dest parent_process_name process_name process_path process process_id dest_port C2
| `searchprotocolhost_with_no_command_line_with_network_filter`
GPUpdate with no Command Line Arguments with Network
- source: splunk
- technicques:
- T1055
Description
The following analytic detects the execution of gpupdate.exe without command line arguments and with an active network connection. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process execution and network traffic data. It is significant because gpupdate.exe typically runs with specific arguments, and its execution without them, especially with network activity, is often associated with malicious software like Cobalt Strike. If confirmed malicious, this activity could indicate an attacker leveraging gpupdate.exe for lateral movement, command and control, or other nefarious purposes, potentially leading to system compromise.
Detection logic
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where Processes.process_name=gpupdate.exe 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)`
| regex process="(?i)(gpupdate\.exe.{0,4}$)"
| join process_id [
| tstats `security_content_summariesonly` count values(All_Traffic.app) as app values(All_Traffic.dest_ip) as dest_ip values(All_Traffic.direction) as direction values(All_Traffic.dvc) as dvc values(All_Traffic.protocol) as protocol values(All_Traffic.protocol_version) as protocol_version values(All_Traffic.src) as src values(All_Traffic.src_ip) as src_ip values(All_Traffic.src_port) as src_port values(All_Traffic.transport) as transport FROM datamodel=Network_Traffic.All_Traffic where All_Traffic.dest_port != 0 by All_Traffic.process_id All_Traffic.dest All_Traffic.dest_port
| `drop_dm_object_name(All_Traffic)`
| rename dest as C2 ]
| table _time user dest parent_process_name process_name process_path process process_id dest_port C2 app dest_ip direction dvc protocol protocol_version src src_ip src_port transport
| `gpupdate_with_no_command_line_arguments_with_network_filter`
Suspicious DLLHost no Command Line Arguments
- source: splunk
- technicques:
- T1055
Description
The following analytic detects instances of DLLHost.exe executing without command line arguments. This behavior is unusual and often associated with malicious activities, such as those performed by Cobalt Strike. The detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs. This activity is significant because DLLHost.exe typically requires arguments to function correctly, and its absence may indicate an attempt to evade detection. If confirmed malicious, this could lead to unauthorized actions like credential dumping or file manipulation, posing a severe threat to the environment.
Detection logic
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where `process_dllhost` 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)`
| regex process="(?i)(dllhost\.exe.{0,4}$)"
| `suspicious_dllhost_no_command_line_arguments_filter`
Suspicious GPUpdate no Command Line Arguments
- source: splunk
- technicques:
- T1055
Description
The following analytic detects the execution of gpupdate.exe without any command line arguments. This behavior is identified using data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs. It is significant because gpupdate.exe typically runs with specific arguments, and its execution without them is often associated with malicious activities, such as those performed by Cobalt Strike. If confirmed malicious, this activity could indicate an attempt to execute unauthorized commands or scripts, potentially leading to further system compromise or lateral movement within the network.
Detection logic
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where `process_gpupdate` 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)`
| regex process="(?i)(gpupdate\.exe.{0,4}$)"
| `suspicious_gpupdate_no_command_line_arguments_filter`