LoFP LoFP / false positives may be present if the application is legitimately used, filter by user or endpoint as needed.

Techniques

Sample rules

Windows AutoIt3 Execution

Description

The following analytic is designed to detect any execution of AutoIt3, a scripting language designed for automating the Windows GUI and general scripting. This includes instances where AutoIt3 has been renamed or otherwise altered in an attempt to evade detection. The analytic works by searching for process names or original file names that match ‘autoit3.exe’, which is the default executable for AutoIt scripts. This detection is important as AutoIt3 is often used by attackers to automate malicious activities, such as the execution of malware or other unwanted software. False positives may occur with legitimate uses of AutoIt3.

Detection logic


| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name IN ("autoit3.exe", "autoit*.exe") OR Processes.original_file_name IN ("autoit3.exe", "autoit*.exe") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_autoit3_execution_filter`

Windows ConHost with Headless Argument

Description

The following analytic detects the unusual use of the Windows Console Host process (conhost.exe) with the undocumented –headless parameter to spawn a new process. This behavior is highly unusual and indicative of suspicious activity, as the –headless parameter is not commonly used in legitimate operations. The analytic identifies this behavior by looking for instances where conhost.exe is invoked with the –headless argument. This behavior is worth identifying for a Security Operations Center (SOC) as it could indicate an attacker’s attempt to execute commands or scripts in a stealthy manner, potentially to establish persistence, perform lateral movement, or carry out other malicious activities. If a true positive is identified, it suggests that an attacker has gained a foothold in the environment and is attempting to further their attack, which could lead to serious consequences such as data exfiltration, system compromise, or deployment of ransomware. Potential false positives could arise from legitimate administrative activity, hence it is important to validate the context of the detected behavior during triage.

Detection logic


| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=conhost.exe Processes.process="*--headless *" by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_conhost_with_headless_argument_filter`