{"id":"2267fe65-0681-42ad-9a6d-46553d3f3480","title":"WSL Child Process Anomaly","description":"Detects uncommon or suspicious child processes spawning from a WSL process. This could indicate an attempt to evade parent/child relationship detections or persistence attempts via cron using WSL","author":"Nasreddine Bencherchali (Nextron Systems)","status":"test","level":"medium","date":"2023-01-23","modified":"2023-08-15","tags":["attack.execution","attack.stealth","attack.t1218","attack.t1202"],"technique_ids":["T1202","T1218"],"logsource":{"category":"process_creation","product":"windows"},"falsepositives":["Unknown"],"references":["https://lolbas-project.github.io/lolbas/OtherMSBinaries/Wsl/","https://twitter.com/nas_bench/status/1535431474429808642"],"source_path":"rules/windows/process_creation/proc_creation_win_wsl_child_processes_anomalies.yml","source_sha256":"4cbc80b0bcbebc0f33919a6d92bdffe36efa02e2a33e78d497ef5dd56d716a56","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_wsl_child_processes_anomalies.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: WSL Child Process Anomaly\nid: 2267fe65-0681-42ad-9a6d-46553d3f3480\nrelated:\n    - id: dec44ca7-61ad-493c-bfd7-8819c5faa09b # LOLBIN Rule\n      type: derived\nstatus: test\ndescription: Detects uncommon or suspicious child processes spawning from a WSL process. This could indicate an attempt to evade parent/child relationship detections or persistence attempts via cron using WSL\nreferences:\n    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Wsl/\n    - https://twitter.com/nas_bench/status/1535431474429808642\nauthor: Nasreddine Bencherchali (Nextron Systems)\ndate: 2023-01-23\nmodified: 2023-08-15\ntags:\n    - attack.execution\n    - attack.stealth\n    - attack.t1218\n    - attack.t1202\nlogsource:\n    category: process_creation\n    product: windows\ndetection:\n    selection_parent:\n        ParentImage|endswith:\n            - '\\wsl.exe'\n            - '\\wslhost.exe'\n    selection_children_images:\n        Image|endswith:\n            # Add more suspicious/uncommon \"lolbin\" processes\n            - '\\calc.exe'\n            - '\\cmd.exe'\n            - '\\cscript.exe'\n            - '\\mshta.exe'\n            - '\\powershell.exe'\n            - '\\pwsh.exe'\n            - '\\regsvr32.exe'\n            - '\\rundll32.exe'\n            - '\\wscript.exe'\n    selection_children_paths:\n        Image|contains:\n            - '\\AppData\\Local\\Temp\\'\n            - 'C:\\Users\\Public\\'\n            - 'C:\\Windows\\Temp\\'\n            - 'C:\\Temp\\'\n            - '\\Downloads\\'\n            - '\\Desktop\\'\n    condition: selection_parent and 1 of selection_children_*\nfalsepositives:\n    - Unknown\nlevel: medium\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1202","id":"T1202","name":"Indirect Command Execution","page":"techniques/enterprise/T1202/"},{"key":"enterprise/T1218","id":"T1218","name":"System Binary Proxy Execution","page":"techniques/enterprise/T1218/"}],"data_path":"data/detection-rules/2267fe65-0681-42ad-9a6d-46553d3f3480.json","kind":"sigma"}