Query: detect Detects cmd.exe executing commands with the "start" utility using "/b" (no window) or "/min" (minimized) flags. To reduc in logs
Matching passage: Sigma rule: Detects cmd.exe executing commands with the "start" utility using "/b" (no window) or "/min" (minimized) flags. To reduc. Logsource: windows / process_creation. Rule: title: Cmd Launched with Hidden Start Flags to Suspicious Targets id: 5a6b7c8d-9e0f-1a2b-3c4d-5e6f7a8b9c0d status: experimental description: 'Detects cmd.exe executing commands with the "start" utility using "/b" (no window) or "/min" (minimized) flags. To reduce false positives from standard background tasks, detection is restricted to scenarios where the target is a known script extension or located in suspicious temporary/public directories. This technique was observed in Chaos, DarkSide, and Emotet malware campaigns. ' references: - https://www.fortinet.com/blog/threat-research/evolution-of-chaos-ransomware-faster-smarter-and-more-dangerous - https://www.fortinet.com/blog/threat-research/newly-discovered-function-in-darkside-ransomware-variant-targets-disk-partitions - https://www.fortinet.com/blog/threat-research/ms-office-files-involved-in-emotet-trojan-campaign-pt-one - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/start tags: - attack.stealth - attack.t1564.003 author: Vladan Sekulic, Swachchhanda Shrawan Poudel (Nextron Systems) date: 2026-01-24 logsource: category: process_creation product: windows detection: selection_cmd_img: - Image|endswith: \cmd.exe - OriginalFileName: Cmd.Exe selection_cmd_hidden_start_1: CommandLine|contains|windash: - 'start ' - start/b - start/min selection_cmd_hidden_start_2: CommandLine|contains|windash: - '/b ' - /b" - '/min ' - /min" selection_cli_uncommon_location: CommandLine|contains: - :\Perflogs\ - :\Temp\ - :\Users\Default\ - :\Windows\Temp\ - \AppData\Roaming\ - \Contacts\ - \Documents\ - \Downloads\ - \Favorites\ - \Favourites\ - \inetpub\ - \Music\ - \Photos\ - \Temporary Internet\ - \Users\Public\ - \Videos\ selection_cli_susp_extension: CommandLine|contains: - .bat - .cmd - .cpl - .hta - .js - .ps1 - .scr - .vbe - .vbs selection_cli_susp_pattern: CommandLine|contains: - ' -nop ' - ' -sta ' - .downloadfile( - .downloadstring( - '-noni ' - '-w hidden ' condition: all of selection_cmd_* and 1 of selection_cli_* falsepositives: - Legitimate administrative scripts running from temporary folders. - Niche software updaters utilizing hidden batch files in ProgramData. level: medium regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_cmd_launched_with_hidden_start_flag/info.yml
Near-miss passage: Sigma rule: Detects the pattern of a UAC bypass using Windows Event Viewer. Logsource: windows / file_event. Rule: title: UAC Bypass Using EventVwr id: 63e4f530-65dc-49cc-8f80-ccfa95c69d43 status: test description: Detects the pattern of a UAC bypass using Windows Event Viewer references: - https://twitter.com/orange_8361/status/1518970259868626944?s=20&t=RFXqZjtA7tWM3HxqEH78Aw - https://twitter.com/splinter_code/status/1519075134296006662?s=12&t=DLUXH86WtcmG_AZ5gY3C6g - https://lolbas-project.github.io/lolbas/Binaries/Eventvwr/#execute author: Antonio Cocomazzi (idea), Florian Roth (Nextron Systems) date: 2022-04-27 modified: 2022-11-22 tags: - attack.privilege-escalation - attack.stealth logsource: category: file_event product: windows detection: selection: TargetFilename|endswith: - \Microsoft\Event Viewer\RecentViews - \Microsoft\EventV~1\RecentViews filter: Image|startswith: - C:\Windows\System32\ - C:\Windows\SysWOW64\ condition: selection and not filter falsepositives: - Unknown level: high