Query: Sigma rule for Detects the execution of "reg.exe" to alter registry keys that would replace the user's desktop background. This is a co
Matching passage: Sigma rule: Detects the execution of "reg.exe" to alter registry keys that would replace the user's desktop background. This is a co. Logsource: windows / process_creation. Rule: title: Potentially Suspicious Desktop Background Change Using Reg.EXE id: 8cbc9475-8d05-4e27-9c32-df960716c701 related: - id: 85b88e05-dadc-430b-8a9e-53ff1cd30aae type: similar status: test description: 'Detects the execution of "reg.exe" to alter registry keys that would replace the user''s desktop background. This is a common technique used by malware to change the desktop background to a ransom note or other image. ' references: - https://www.attackiq.com/2023/09/20/emulating-rhysida/ - https://research.checkpoint.com/2023/the-rhysida-ransomware-activity-analysis-and-ties-to-vice-society/ - https://www.trendmicro.com/en_us/research/23/h/an-overview-of-the-new-rhysida-ransomware.html - https://www.virustotal.com/gui/file/a864282fea5a536510ae86c77ce46f7827687783628e4f2ceb5bf2c41b8cd3c6/behavior - https://admx.help/?Category=Windows_10_2016&Policy=Microsoft.Policies.WindowsDesktop::Wallpaper - https://admx.help/?Category=Windows_10_2016&Policy=Microsoft.Policies.ControlPanelDisplay::CPL_Personalization_NoDesktopBackgroundUI author: Stephen Lincoln @slincoln-aiq (AttackIQ) date: 2023-12-21 tags: - attack.persistence - attack.impact - attack.defense-impairment - attack.t1112 - attack.t1491.001 logsource: product: windows category: process_creation detection: selection_reg_img: - Image|endswith: \reg.exe - OriginalFileName: reg.exe selection_reg_flag: CommandLine|contains: add selection_keys: CommandLine|contains: - Control Panel\Desktop - CurrentVersion\Policies\ActiveDesktop - CurrentVersion\Policies\System selection_cli_reg_1: CommandLine|contains|all: - /v NoChangingWallpaper - /d 1 selection_cli_reg_2: CommandLine|contains|all: - /v Wallpaper - /t REG_SZ selection_cli_reg_3: CommandLine|contains|all: - /v WallpaperStyle - /d 2 condition: all of selection_reg_* and selection_keys and 1 of selection_cli_reg_* falsepositives: - Administrative scripts that change the desktop background to a company logo or other image. level: medium
Near-miss passage: Sigma rule: Identifies when a privilege role can be activated without performing mfa.. Logsource: azure / pim. Rule: title: Roles Activation Doesn't Require MFA id: 94a66f46-5b64-46ce-80b2-75dcbe627cc0 status: test description: Identifies when a privilege role can be activated without performing mfa. references: - https://learn.microsoft.com/en-us/entra/id-governance/privileged-identity-management/pim-how-to-configure-security-alerts#roles-dont-require-multi-factor-authentication-for-activation author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo' date: 2023-09-14 tags: - attack.initial-access - attack.stealth - attack.t1078 - attack.persistence - attack.privilege-escalation logsource: product: azure service: pim detection: selection: riskEventType: noMfaOnRoleActivationAlertIncident condition: selection falsepositives: - Investigate if user is performing MFA at sign-in. level: high