Query: alert when Detects suspicious ways to download files from Microsoft domains that are used to store attachments in Emails or OneNote
Matching passage: Sigma rule: Detects suspicious ways to download files from Microsoft domains that are used to store attachments in Emails or OneNote. Logsource: windows / process_creation. Rule: title: Suspicious Download from Office Domain id: 00d49ed5-4491-4271-a8db-650a4ef6f8c1 status: test description: Detects suspicious ways to download files from Microsoft domains that are used to store attachments in Emails or OneNote documents references: - https://twitter.com/an0n_r0/status/1474698356635193346?s=12 - https://twitter.com/mrd0x/status/1475085452784844803?s=12 author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems) date: 2021-12-27 modified: 2022-08-02 tags: - attack.command-and-control - attack.resource-development - attack.t1105 - attack.t1608 logsource: product: windows category: process_creation detection: selection_download: - Image|endswith: - \curl.exe - \wget.exe - CommandLine|contains: - Invoke-WebRequest - 'iwr ' - 'curl ' - 'wget ' - Start-BitsTransfer - .DownloadFile( - .DownloadString( selection_domains: CommandLine|contains: - https://attachment.outlook.live.net/owa/ - https://onenoteonlinesync.onenote.com/onenoteonlinesync/ condition: all of selection_* falsepositives: - Scripts or tools that download attachments from these domains (OneNote, Outlook 365) level: high
Near-miss passage: Sigma rule: Detects when the Notepad++ updater (gup.exe) creates files in suspicious or uncommon locations. This could indicate pote. Logsource: windows / file_event. Rule: title: Uncommon File Created by Notepad++ Updater Gup.EXE id: 3b8f4c92-6a51-4d7e-9c3a-8e2d1f5a7b09 status: experimental description: 'Detects when the Notepad++ updater (gup.exe) creates files in suspicious or uncommon locations. This could indicate potential exploitation of the updater component to deliver unwanted malware or unwarranted files. ' references: - https://notepad-plus-plus.org/news/v889-released/ - https://www.heise.de/en/news/Notepad-updater-installed-malware-11109726.html - https://www.rapid7.com/blog/post/tr-chrysalis-backdoor-dive-into-lotus-blossoms-toolkit/ - https://www.validin.com/blog/exploring_notepad_plus_plus_network_indicators/ - https://securelist.com/notepad-supply-chain-attack/118708/ author: Swachchhanda Shrawan Poudel (Nextron Systems) date: 2026-02-03 modified: 2026-03-16 tags: - attack.collection - attack.credential-access - attack.t1195.002 - attack.initial-access - attack.t1557 logsource: category: file_event product: windows detection: selection: Image|endswith: \gup.exe filter_main_legit_paths: TargetFilename|startswith: - C:\Program Files\Notepad++\ - C:\Program Files (x86)\Notepad++\ filter_main_temp_update_installer: TargetFilename|startswith: C:\Users\ TargetFilename|contains|all: - \AppData\Local\Temp\ - npp. - .Installer. - .exe filter_main_temp_generic_zip: TargetFilename|startswith: C:\Users\ TargetFilename|contains|all: - \AppData\Local\Temp\ - .zip filter_main_recycle_bin: TargetFilename|startswith: C:\$Recycle.Bin\S-1-5-21 filter_main_plugins: - TargetFilename|contains: - \plugins\JsonTools\testfiles\ - \Notepad++\plugins\ComparePlugin\ - TargetFilename|contains|all: - npp. - .portable. - \plugins\ condition: selection and not 1 of filter_main_* falsepositives: - Custom or portable Notepad++ installations in non-standard directories. - Legitimate update processes creating temporary files in unexpected locations. level: high