Detect Msiexec in Microsoft Sentinel
Adversaries may abuse msiexec.exe to proxy execution of malicious payloads. Msiexec.exe is the command-line utility for the Windows Installer and is commonly associated with executing installation packages (.msi). Since it is a signed Microsoft binary, msiexec.exe can bypass application control solutions. Adversaries use it to launch local or remote MSI files and to execute DLLs. Execution may also be elevated to SYSTEM if the AlwaysInstallElevated policy is enabled. Widely abused by malware families including QakBot, IcedID, Emotet, Clop, Maze, Ragnar Locker, Latrodectus, Raspberry Robin, TA505, Rancor, ZIRCONIUM, and many others.
MITRE ATT&CK
- Tactic
- Defense Evasion
- Technique
- T1218 System Binary Proxy Execution
- Sub-technique
- T1218.007 Msiexec
- Canonical reference
- https://attack.mitre.org/techniques/T1218/007/
KQL Detection Query
DeviceProcessEvents
| where Timestamp > ago(24h)
| where FileName =~ "msiexec.exe"
| extend RemoteMSI = ProcessCommandLine has_any ("http://", "https://", "ftp://")
| extend UNCPath = ProcessCommandLine matches regex @"\\\\.+\\\.+\.msi"
| extend SilentInstall = ProcessCommandLine has_any ("/q", "/quiet", "/passive")
| extend DLLExecution = ProcessCommandLine has "/y"
| extend SuspiciousPath = ProcessCommandLine has_any ("Temp", "AppData", "Downloads", "Public", "Desktop")
| extend SuspiciousParent = InitiatingProcessFileName has_any ("cmd.exe", "powershell.exe", "wscript.exe", "cscript.exe", "mshta.exe", "winword.exe", "excel.exe", "outlook.exe")
| extend PropertyPair = ProcessCommandLine matches regex @"[A-Z]+=.{10,}"
| where RemoteMSI or DLLExecution or (SilentInstall and SuspiciousPath) or (SuspiciousParent and SuspiciousPath) or SuspiciousParent
| project Timestamp, DeviceName, AccountName, ProcessCommandLine, InitiatingProcessFileName,
InitiatingProcessCommandLine, RemoteMSI, SilentInstall, DLLExecution, SuspiciousPath, SuspiciousParent, PropertyPair
| sort by Timestamp descDetects msiexec.exe abuse across key patterns: remote MSI loading via URL, DLL execution via /y flag, silent installation from suspicious paths, suspicious parent processes (scripting engines, Office apps), and UNC-path MSI loading. The property pair pattern catches Duqu-style key-passing techniques.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate software deployment via SCCM, Intune, or PDQ Deploy which frequently calls msiexec.exe with /quiet or /passive flags
- System updates and Windows Update installation processes that use msiexec.exe with silent flags
- IT administrators manually installing software packages with administrative flags
- Software auto-update mechanisms that download and install MSI packages remotely
Other platforms for T1218.007
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Msiexec Remote MSI Execution
Expected signal: Sysmon Event ID 1: msiexec.exe with URL and /q flag. Sysmon Event ID 3: Network connection attempt to 127.0.0.1:8080. Security Event ID 4688. The installation will fail (no server) but the process creation event fires.
- Test 2Msiexec DLL Execution via /y Flag
Expected signal: Sysmon Event ID 11: DLL written to Temp. Sysmon Event ID 1: msiexec.exe with /y flag and Temp path. Sysmon Event ID 7 (Image Load) for the DLL being loaded by msiexec.
- Test 3Msiexec Silent Install from Temp Directory via PowerShell
Expected signal: Sysmon Event ID 1: powershell.exe, then msiexec.exe with /q and Temp path, ParentImage=powershell.exe. Both SuspiciousParent and SuspiciousPath fire. Security Event ID 4688 for both.
References (6)
- https://attack.mitre.org/techniques/T1218/007/
- https://lolbas-project.github.io/lolbas/Binaries/Msiexec/
- https://blog.trendmicro.com/trendlabs-security-intelligence/attack-using-windows-installer-msiexec-exe-leads-lokibot/
- https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/msiexec
- https://docs.microsoft.com/en-us/windows/win32/msi/alwaysinstallelevated
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.007/T1218.007.md
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