{"id":"84b14121-9d14-416e-800b-f3b829c5a14d","title":"Suspicious CustomShellHost Execution","description":"Detects the execution of CustomShellHost.exe where the child isn't located in 'C:\\Windows\\explorer.exe'. CustomShellHost is a known LOLBin that can be abused by attackers for defense evasion techniques.\n","author":"Nasreddine Bencherchali (Nextron Systems)","status":"test","level":"high","date":"2022-08-19","modified":"2025-10-29","tags":["attack.stealth","attack.t1216"],"technique_ids":["T1216"],"logsource":{"category":"process_creation","product":"windows"},"falsepositives":["False positives are unlikely, investigate matches carefully."],"references":["https://github.com/LOLBAS-Project/LOLBAS/pull/180","https://lolbas-project.github.io/lolbas/Binaries/CustomShellHost/"],"source_path":"rules/windows/process_creation/proc_creation_win_customshellhost_susp_exec.yml","source_sha256":"ecf3532694b5bc13d3be81aa1a925108d2d89a1a6e9566a647fa2693c2dd65e8","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_customshellhost_susp_exec.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Suspicious CustomShellHost Execution\nid: 84b14121-9d14-416e-800b-f3b829c5a14d\nstatus: test\ndescription: |\n    Detects the execution of CustomShellHost.exe where the child isn't located in 'C:\\Windows\\explorer.exe'. CustomShellHost is a known LOLBin that can be abused by attackers for defense evasion techniques.\nreferences:\n    - https://github.com/LOLBAS-Project/LOLBAS/pull/180\n    - https://lolbas-project.github.io/lolbas/Binaries/CustomShellHost/\nauthor: Nasreddine Bencherchali (Nextron Systems)\ndate: 2022-08-19\nmodified: 2025-10-29\ntags:\n    - attack.stealth\n    - attack.t1216\nlogsource:\n    category: process_creation\n    product: windows\ndetection:\n    selection:\n        ParentImage|endswith: '\\CustomShellHost.exe'\n    filter_main_explorer:\n        Image: 'C:\\Windows\\explorer.exe'\n    condition: selection and not 1 of filter_main_*\nfalsepositives:\n    - False positives are unlikely, investigate matches carefully.\nlevel: high\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1216","id":"T1216","name":"System Script Proxy Execution","page":"techniques/enterprise/T1216/"}],"data_path":"data/detection-rules/84b14121-9d14-416e-800b-f3b829c5a14d.json","kind":"sigma"}