Query: write Sigma for Detects modification of Windows Registry Classes keys used for persistence. Adversaries modify these autostart extensibi
Matching passage: Sigma rule: Detects modification of Windows Registry Classes keys used for persistence. Adversaries modify these autostart extensibi. Logsource: windows / registry_set. Rule: title: Classes Autorun Keys Modification id: 9df5f547-c86a-433e-b533-f2794357e242 related: - id: 17f878b8-9968-4578-b814-c4217fc5768c type: obsolete status: test description: 'Detects modification of Windows Registry Classes keys used for persistence. Adversaries modify these autostart extensibility points (ASEP) to execute malicious code when file types are opened or actions are performed. Various legitimate software also uses these keys. Currently, this rule only filters out known legitimate software paths, thus it is recommended to review and tune filters for your environment to reduce false positives before deploying to production. ' references: - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1547.001/T1547.001.md - https://learn.microsoft.com/en-us/sysinternals/downloads/autoruns - https://gist.github.com/GlebSukhodolskiy/0fc5fa5f482903064b448890db1eaf9d author: Victor Sergeev, Daniil Yugoslavskiy, Gleb Sukhodolskiy, Timur Zinniatullin, oscd.community, Tim Shelton, frack113 (split) date: 2019-10-25 modified: 2025-10-22 tags: - attack.privilege-escalation - attack.persistence - attack.t1547.001 logsource: category: registry_set product: windows detection: selection_classes_base: TargetObject|contains: \Software\Classes selection_classes_target: TargetObject|contains: - \Folder\ShellEx\ExtShellFolderViews - \Folder\ShellEx\DragDropHandlers - \Folder\Shellex\ColumnHandlers - \Filter - \Exefile\Shell\Open\Command\(Default) - \Directory\Shellex\DragDropHandlers - \Directory\Shellex\CopyHookHandlers - \CLSID\{AC757296-3522-4E11-9862-C17BE5A1767E}\Instance - \CLSID\{ABE3B9A4-257D-4B97-BD1A-294AF496222E}\Instance - \CLSID\{7ED96837-96F0-4812-B211-F13C24117ED3}\Instance - \CLSID\{083863F1-70DE-11d0-BD40-00A0C911CE86}\Instance - \Classes\AllFileSystemObjects\ShellEx\DragDropHandlers - \.exe - \.cmd - \ShellEx\PropertySheetHandlers - \ShellEx\ContextMenuHandlers filter_main_drivers: Image: C:\Windows\System32\drvinst.exe filter_main_empty: Details: (Empty) filter_main_null: Details: null filter_main_svchost: Image: C:\Windows\System32\svchost.exe TargetObject|contains: \lnkfile\shellex\ContextMenuHandlers\ filter_optional_msoffice: Details: '{807583E5-5146-11D5-A672-00B0D022E945}' condition: all of selection_* and not 1 of filter_main_* and not 1 of filter_optional_* falsepositives: - Legitimate software automatically (mostly, during installation) sets up autorun keys for legitimate reason - Legitimate admi
Near-miss passage: Sigma rule: Detects the use of Python's base64 decoding functions in command line executions on Linux systems. Malicious scripts oft. Logsource: linux / process_creation. Rule: title: Python One-Liners with Base64 Decoding - Linux id: 55e862a8-dd9c-4651-807a-f21fcad56716 related: - id: 50a0aa3d-ab16-4594-a8aa-5145a6e6792b type: similar status: experimental description: 'Detects the use of Python''s base64 decoding functions in command line executions on Linux systems. Malicious scripts often use python one-liners to decode and execute base64-encoded payloads, which is a common technique for obfuscation and evasion. ' references: - https://docs.python.org/3/library/base64.html - https://www.virustotal.com/gui/file/bc43e925d7b4b74319f6e74e836a96f1997ba404e14ac566cf12a21e9da463db/behavior - https://cloud.google.com/blog/topics/threat-intelligence/cybercriminals-weaponize-fake-ai-websites author: Hugh Ryan (HueCodes), Swachchhanda Shrawan Poudel (Nextron Systems) date: 2026-03-09 tags: - attack.execution - attack.stealth - attack.t1059.006 - attack.t1027.010 logsource: category: process_creation product: linux detection: selection_img: Image|contains: /python selection_cli: CommandLine|contains|all: - import - base64 - ' -c' CommandLine|contains: - .decode - b16decode - b32decode - b32hexdecode - b64decode - b85decode - z85decode condition: all of selection_* falsepositives: - Legitimate use of Python for decoding data, which is uncommon in typical enterprise environments but possible in development or data analysis contexts. level: high