{"id":"98767d61-b2e8-4d71-b661-e36783ee24c1","title":"Gzip Archive Decode Via PowerShell","description":"Detects attempts of decoding encoded Gzip archives via PowerShell.","author":"Hieu Tran","status":"test","level":"medium","date":"2023-03-13","modified":"","tags":["attack.command-and-control","attack.t1132.001"],"technique_ids":["T1132.001"],"logsource":{"product":"windows","category":"process_creation"},"falsepositives":["Legitimate administrative scripts may use this functionality. Use \"ParentImage\" in combination with the script names and allowed users and applications to filter legitimate executions"],"references":["https://www.zscaler.com/blogs/security-research/onenote-growing-threat-malware-distribution"],"source_path":"rules/windows/process_creation/proc_creation_win_powershell_decode_gzip.yml","source_sha256":"f4d17159b673eef4c41711bd398e336f838028295e00ef9b4148b438030a611f","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_powershell_decode_gzip.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Gzip Archive Decode Via PowerShell\nid: 98767d61-b2e8-4d71-b661-e36783ee24c1\nstatus: test\ndescription: Detects attempts of decoding encoded Gzip archives via PowerShell.\nreferences:\n    - https://www.zscaler.com/blogs/security-research/onenote-growing-threat-malware-distribution\nauthor: Hieu Tran\ndate: 2023-03-13\ntags:\n    - attack.command-and-control\n    - attack.t1132.001\nlogsource:\n    product: windows\n    category: process_creation\ndetection:\n    selection:\n        CommandLine|contains|all:\n            - 'GZipStream'\n            - '::Decompress'\n    condition: selection\nfalsepositives:\n    - Legitimate administrative scripts may use this functionality. Use \"ParentImage\" in combination with the script names and allowed users and applications to filter legitimate executions\nlevel: medium\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1132.001","id":"T1132.001","name":"Standard Encoding","page":"techniques/enterprise/T1132.001/"}],"data_path":"data/detection-rules/98767d61-b2e8-4d71-b661-e36783ee24c1.json","kind":"sigma"}