{"id":"4358e5a5-7542-4dcb-b9f3-87667371839b","title":"ISO or Image Mount Indicator in Recent Files","description":"Detects the creation of recent element file that points to an .ISO, .IMG, .VHD or .VHDX file as often used in phishing attacks.\nThis can be a false positive on server systems but on workstations users should rarely mount .iso or .img files.\n","author":"Florian Roth (Nextron Systems)","status":"test","level":"medium","date":"2022-02-11","modified":"","tags":["attack.initial-access","attack.t1566.001"],"technique_ids":["T1566.001"],"logsource":{"product":"windows","category":"file_event"},"falsepositives":["Cases in which a user mounts an image file for legitimate reasons"],"references":["https://www.microsoft.com/security/blog/2021/05/27/new-sophisticated-email-based-attack-from-nobelium/","https://www.trendmicro.com/vinfo/us/security/news/cybercrime-and-digital-threats/malicious-spam-campaign-uses-iso-image-files-to-deliver-lokibot-and-nanocore","https://blog.emsisoft.com/en/32373/beware-new-wave-of-malware-spreads-via-iso-file-email-attachments/","https://insights.sei.cmu.edu/blog/the-dangers-of-vhd-and-vhdx-files/"],"source_path":"rules/windows/file/file_event/file_event_win_iso_file_recent.yml","source_sha256":"b1494df69b487c66570fa444013659932a89d3ab47fb177442a5758ee263c9a3","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/file/file_event/file_event_win_iso_file_recent.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: ISO or Image Mount Indicator in Recent Files\nid: 4358e5a5-7542-4dcb-b9f3-87667371839b\nstatus: test\ndescription: |\n    Detects the creation of recent element file that points to an .ISO, .IMG, .VHD or .VHDX file as often used in phishing attacks.\n    This can be a false positive on server systems but on workstations users should rarely mount .iso or .img files.\nreferences:\n    - https://www.microsoft.com/security/blog/2021/05/27/new-sophisticated-email-based-attack-from-nobelium/\n    - https://www.trendmicro.com/vinfo/us/security/news/cybercrime-and-digital-threats/malicious-spam-campaign-uses-iso-image-files-to-deliver-lokibot-and-nanocore\n    - https://blog.emsisoft.com/en/32373/beware-new-wave-of-malware-spreads-via-iso-file-email-attachments/\n    - https://insights.sei.cmu.edu/blog/the-dangers-of-vhd-and-vhdx-files/\nauthor: Florian Roth (Nextron Systems)\ndate: 2022-02-11\ntags:\n    - attack.initial-access\n    - attack.t1566.001\nlogsource:\n    product: windows\n    category: file_event\ndetection:\n    selection:\n        TargetFilename|endswith:\n            - '.iso.lnk'\n            - '.img.lnk'\n            - '.vhd.lnk'\n            - '.vhdx.lnk'\n        TargetFilename|contains: '\\Microsoft\\Windows\\Recent\\'\n    condition: selection\nfalsepositives:\n    - Cases in which a user mounts an image file for legitimate reasons\nlevel: medium\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1566.001","id":"T1566.001","name":"Spearphishing Attachment","page":"techniques/enterprise/T1566.001/"}],"data_path":"data/detection-rules/4358e5a5-7542-4dcb-b9f3-87667371839b.json","kind":"sigma"}