Query: alert when Detects the creation of files with suspicious file extensions in the temporary directory that Outlook uses when opening
Matching passage: Sigma rule: Detects the creation of files with suspicious file extensions in the temporary directory that Outlook uses when opening. Logsource: windows / file_event. Rule: title: Suspicious File Created in Outlook Temporary Directory id: fabb0e80-030c-4e3e-a104-d09676991ac3 related: - id: f748c45a-f8d3-4e6f-b617-fe176f695b8f type: obsolete status: experimental description: 'Detects the creation of files with suspicious file extensions in the temporary directory that Outlook uses when opening attachments. This can be used to detect spear-phishing campaigns that use suspicious files as attachments, which may contain malicious code. ' references: - https://vipre.com/blog/svg-phishing-attacks-the-new-trick-in-the-cybercriminals-playbook/ - https://thecyberexpress.com/rogue-rdp-files-used-in-ukraine-cyberattacks/ - https://www.microsoft.com/en-us/security/blog/2024/10/29/midnight-blizzard-conducts-large-scale-spear-phishing-campaign-using-rdp-files/ author: Florian Roth (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems) date: 2025-07-22 tags: - attack.initial-access - attack.t1566.001 logsource: product: windows category: file_event detection: selection_extension: TargetFilename|endswith: - .cpl - .hta - .iso - .rdp - .svg - .vba - .vbe - .vbs selection_location: - TargetFilename|contains: - \AppData\Local\Packages\Microsoft.Outlook_ - \AppData\Local\Microsoft\Olk\Attachments\ - TargetFilename|contains|all: - \AppData\Local\Microsoft\Windows\ - \Content.Outlook\ condition: all of selection_* falsepositives: - Opening of headers or footers in email signatures that include SVG images or legitimate SVG attachments level: high
Near-miss passage: Sigma rule: Adversaries may execute their own malicious payloads by hijacking the Registry entries used by services. Adversaries may. Logsource: windows / process_creation. Rule: title: Changing Existing Service ImagePath Value Via Reg.EXE id: 9b0b7ac3-6223-47aa-a3fd-e8f211e637db status: test description: 'Adversaries may execute their own malicious payloads by hijacking the Registry entries used by services. Adversaries may use flaws in the permissions for registry to redirect from the originally specified executable to one that they control, in order to launch their own code at Service start. Windows stores local service configuration information in the Registry under HKLM\SYSTEM\CurrentControlSet\Services ' references: - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1574.011/T1574.011.md#atomic-test-2---service-imagepath-change-with-regexe author: frack113 date: 2021-12-30 modified: 2024-03-13 tags: - attack.privilege-escalation - attack.persistence - attack.execution - attack.stealth - attack.t1574.011 logsource: category: process_creation product: windows detection: selection: Image|endswith: \reg.exe CommandLine|contains|all: - 'add ' - SYSTEM\CurrentControlSet\Services\ - ' ImagePath ' selection_value: CommandLine|contains|windash: ' -d ' condition: all of selection* falsepositives: - Unknown level: medium