The hypothesis is that the presence of the “dubseven_dropper_dialog_remains” YARA rule indicates potential residual artifacts from a malicious dropper, which may be used to identify early-stage compromise. SOC teams should proactively hunt for this behavior in Azure Sentinel to detect and respond to advanced persistent threats before they establish a persistent foothold.
YARA Rule
rule dubseven_dropper_dialog_remains
{
meta:
author = "Matt Brooks, @cmatthewbrooks"
desc = "Searches for related dialog remnants. How rude."
strings:
$dia1 = "fuckMessageBox 1.0" wide
$dia2 = "Rundll 1.0" wide
condition:
//MZ header //PE signature
uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550 and any of them
}
This YARA rule can be deployed in the following contexts:
This rule contains 2 string patterns in its detection logic.
Scenario: A system administrator is using PowerShell to run a legitimate script that creates a temporary dialog box as part of a scheduled maintenance task.
Filter/Exclusion: Exclude processes where the parent process is powershell.exe and the command line includes -Command with a known maintenance script path.
Scenario: A Windows Task Scheduler job is configured to launch a legitimate application that displays a brief dialog box during startup.
Filter/Exclusion: Exclude processes launched by schtasks.exe or with a parent process of Taskeng.exe and check for known legitimate application paths.
Scenario: A Microsoft Endpoint Configuration Manager (MECM) deployment is running a script that shows a user confirmation dialog during software installation.
Filter/Exclusion: Exclude processes with a parent process of ccmexec.exe or where the command line includes MECM-related paths or GUIDs.
Scenario: A Windows Update installation process temporarily displays a dialog box to confirm the installation of a critical update.
Filter/Exclusion: Exclude processes with a parent process of wuauclt.exe or where the command line includes wusa.exe with update package paths.
Scenario: A System Center Operations Manager (SCOM) agent is running a health check that displays a brief dialog to confirm system status.
Filter/Exclusion: Exclude processes with a parent process of HealthService.exe or where the command line includes SCOM-related paths or service names.