{"id":"42a5f1e7-9603-4f6d-97ae-3f37d130d794","title":"Suspicious File Downloaded From File-Sharing Website Via Certutil.EXE","description":"Detects the execution of certutil with certain flags that allow the utility to download files from file-sharing websites.","author":"Nasreddine Bencherchali (Nextron Systems)","status":"test","level":"high","date":"2023-02-15","modified":"2026-03-29","tags":["attack.stealth","attack.t1027","attack.command-and-control","attack.t1105"],"technique_ids":["T1027","T1105"],"logsource":{"category":"process_creation","product":"windows"},"falsepositives":["Unknown"],"references":["https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/certutil","https://forensicitguy.github.io/agenttesla-vba-certutil-download/","https://news.sophos.com/en-us/2021/04/13/compromised-exchange-server-hosting-cryptojacker-targeting-other-exchange-servers/","https://twitter.com/egre55/status/1087685529016193025","https://lolbas-project.github.io/lolbas/Binaries/Certutil/","https://www.microsoft.com/en-us/security/blog/2024/01/17/new-ttps-observed-in-mint-sandstorm-campaign-targeting-high-profile-individuals-at-universities-and-research-orgs/","https://www.hexacorn.com/blog/2020/08/23/certutil-one-more-gui-lolbin"],"source_path":"rules/windows/process_creation/proc_creation_win_certutil_download_file_sharing_domains.yml","source_sha256":"8a36aad4a29cf0a1cc3259b3f5a3431d9f3178ef2108d43bae0915ce7b2a290b","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/process_creation/proc_creation_win_certutil_download_file_sharing_domains.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 File Downloaded From File-Sharing Website Via Certutil.EXE\nid: 42a5f1e7-9603-4f6d-97ae-3f37d130d794\nrelated:\n    - id: 19b08b1c-861d-4e75-a1ef-ea0c1baf202b # Direct IP download\n      type: similar\n    - id: 13e6fe51-d478-4c7e-b0f2-6da9b400a829 # Generic download\n      type: similar\n    - id: 8b48ad89-10d8-4382-a546-50588c410f0d\n      type: similar\n    - id: d635249d-86b5-4dad-a8c7-d7272b788586\n      type: similar\n    - id: 52182dfb-afb7-41db-b4bc-5336cb29b464\n      type: similar\n    - id: ae02ed70-11aa-4a22-b397-c0d0e8f6ea99\n      type: similar\n    - id: e0f8ab85-0ac9-423b-a73a-81b3c7b1aa97\n      type: similar\n    - id: 7b434893-c57d-4f41-908d-6a17bf1ae98f\n      type: similar\n    - id: 8518ed3d-f7c9-4601-a26c-f361a4256a0c\n      type: similar\n    - id: 56454143-524f-49fb-b1c6-3fb8b1ad41fb\n      type: similar\n    - id: b6e04788-29e1-4557-bb14-77f761848ab8\n      type: similar\n    - id: a0d7e4d2-bede-4141-8896-bc6e237e977c\n      type: similar\n    - id: 297ae038-edc2-4b2e-bb3e-7c5fc94dd5c7\n      type: similar\nstatus: test\ndescription: Detects the execution of certutil with certain flags that allow the utility to download files from file-sharing websites.\nreferences:\n    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/certutil\n    - https://forensicitguy.github.io/agenttesla-vba-certutil-download/\n    - https://news.sophos.com/en-us/2021/04/13/compromised-exchange-server-hosting-cryptojacker-targeting-other-exchange-servers/\n    - https://twitter.com/egre55/status/1087685529016193025\n    - https://lolbas-project.github.io/lolbas/Binaries/Certutil/\n    - https://www.microsoft.com/en-us/security/blog/2024/01/17/new-ttps-observed-in-mint-sandstorm-campaign-targeting-high-profile-individuals-at-universities-and-research-orgs/\n    - https://www.hexacorn.com/blog/2020/08/23/certutil-one-more-gui-lolbin\nauthor: Nasreddine Bencherchali (Nextron Systems)\ndate: 2023-02-15\nmodified: 2026-03-29\ntags:\n    - attack.stealth\n    - attack.t1027\n    - attack.command-and-control\n    - attack.t1105\nlogsource:\n    category: process_creation\n    product: windows\ndetection:\n    selection_img:\n        - Image|endswith: '\\certutil.exe'\n        - OriginalFileName: 'CertUtil.exe'\n    selection_flags:\n        CommandLine|contains:\n            - 'urlcache '\n            - 'verifyctl '\n            - 'URL '\n    selection_http:\n        CommandLine|contains:\n            - '.githubusercontent.com'       # Includes both gists and github repositories / Michael Haag (idea)\n            - '0x0.st'\n            - 'anonfiles.com'\n            - 'bashupload.com'\n            - 'cdn.discordapp.com'\n            - 'chunk.io'\n            - 'ddns.net'\n            - 'dl.dropboxusercontent.com'\n            - 'ghostbin.co'\n            - 'github.com'\n            - 'glitch.me'\n            - 'gofile.io'\n            - 'hastebin.com'\n            - 'mediafire.com'\n            - 'mega.nz'\n            - 'onrender.com'\n            - 'pages.dev'\n            - 'paste.ee'\n            - 'pastebin.com'\n            - 'pastebin.pl'\n            - 'pastetext.net'\n            - 'privatlab.com'\n            - 'privatlab.net'\n            - 'send.exploit.in'\n            - 'sendspace.com'\n            - 'storage.googleapis.com'\n            - 'storjshare.io'\n            - 'supabase.co'\n            - 'temp.sh'\n            - 'transfer.sh'\n            - 'trycloudflare.com'\n            - 'ufile.io'\n            - 'w3spaces.com'\n            - 'workers.dev'\n            - 'x0.at'\n    condition: all of selection_*\nfalsepositives:\n    - Unknown\nlevel: high\nregression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_certutil_download_file_sharing_domains/info.yml\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1027","id":"T1027","name":"Obfuscated Files or Information","page":"techniques/enterprise/T1027/"},{"key":"enterprise/T1105","id":"T1105","name":"Ingress Tool Transfer","page":"techniques/enterprise/T1105/"}],"data_path":"data/detection-rules/42a5f1e7-9603-4f6d-97ae-3f37d130d794.json","kind":"sigma"}