Name:High Process Termination Frequency id:17cd75b2-8666-11eb-9ab4-acde48001122 version:5 date:2024-09-30 author:Teoderick Contreras status:production type:Anomaly Description:The following analytic identifies a high frequency of process termination events on a computer within a short period. It leverages Sysmon EventCode 5 logs to detect instances where 15 or more processes are terminated within a 3-second window. This behavior is significant as it is commonly associated with ransomware attempting to avoid exceptions during file encryption. If confirmed malicious, this activity could indicate an active ransomware attack, potentially leading to widespread file encryption and significant data loss. Data_source:
-Sysmon EventID 5
search:`sysmon` EventCode=5 |bin _time span=3s |stats values(Image) as proc_terminated min(_time) as firstTime max(_time) as lastTime count by _time dest EventCode ProcessID | where count >= 15 | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)` | `high_process_termination_frequency_filter`
how_to_implement:To successfully implement this search, you need to be ingesting logs with the Image (process full path of terminated process) from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. known_false_positives:admin or user tool that can terminate multiple process. References: -https://www.mandiant.com/resources/fin11-email-campaigns-precursor-for-ransomware-data-theft -https://blog.virustotal.com/2020/11/keep-your-friends-close-keep-ransomware.html drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Clop Ransomware' - 'LockBit Ransomware' - 'BlackByte Ransomware' - 'Rhysida Ransomware' - 'Snake Keylogger' asset_type:Endpoint confidence:80 impact:90 message:High frequency process termination (more than 15 processes within 3s) detected on host $dest$ mitre_attack_id: - 'T1486' observable: name:'dest' type:'Endpoint' - role: - 'Victim' name:'proc_terminated' type:'Process' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - 'EventCode' - 'Image' - 'dest' - '_time' - 'ProcessID' risk_score:72 security_domain:endpoint
