IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Suspicious Execution via Microsoft Office Add-Ins
editSuspicious Execution via Microsoft Office Add-Ins
editIdentifies execution of common Microsoft Office applications to launch an Office Add-In from a suspicious path or with an unusual parent process. This may indicate an attempt to get initial access via a malicious phishing MS Office Add-In.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.sysmon_operational-*
- endgame-*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Initial Access
- Tactic: Persistence
- Data Source: Elastic Endgame
- Data Source: Elastic Defend
- Data Source: Sysmon
Version: 4
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editprocess where host.os.type == "windows" and event.type == "start" and process.name : ("WINWORD.EXE", "EXCEL.EXE", "POWERPNT.EXE", "MSACCESS.EXE", "VSTOInstaller.exe") and process.args regex~ """.+\.(wll|xll|ppa|ppam|xla|xlam|vsto)""" and /* Office Add-In from suspicious paths */ (process.args : ("?:\\Users\\*\\Temp\\7z*", "?:\\Users\\*\\Temp\\Rar$*", "?:\\Users\\*\\Temp\\Temp?_*", "?:\\Users\\*\\Temp\\BNZ.*", "?:\\Users\\*\\Downloads\\*", "?:\\Users\\*\\AppData\\Roaming\\*", "?:\\Users\\Public\\*", "?:\\ProgramData\\*", "?:\\Windows\\Temp\\*", "\\Device\\*", "http*") or process.parent.name : ("explorer.exe", "OpenWith.exe") or /* Office Add-In from suspicious parent */ process.parent.name : ("cmd.exe", "powershell.exe")) and /* False Positives */ not (process.args : "*.vsto" and process.parent.executable : ("?:\\Program Files\\Logitech\\LogiOptions\\PlugInInstallerUtility*.exe", "?:\\ProgramData\\Logishrd\\LogiOptions\\Plugins\\VSTO\\*\\VSTOInstaller.exe", "?:\\Program Files\\Logitech\\LogiOptions\\PlugInInstallerUtility.exe", "?:\\Program Files\\LogiOptionsPlus\\PlugInInstallerUtility*.exe", "?:\\ProgramData\\Logishrd\\LogiOptionsPlus\\Plugins\\VSTO\\*\\VSTOInstaller.exe", "?:\\Program Files\\Common Files\\microsoft shared\\VSTO\\*\\VSTOInstaller.exe")) and not (process.args : "/Uninstall" and process.name : "VSTOInstaller.exe") and not (process.parent.name : "rundll32.exe" and process.parent.args : "?:\\WINDOWS\\Installer\\MSI*.tmp,zzzzInvokeManagedCustomActionOutOfProc") and not (process.name : "VSTOInstaller.exe" and process.args : "https://dl.getsidekick.com/outlook/vsto/Sidekick.vsto")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Initial Access
- ID: TA0001
- Reference URL: https://attack.mitre.org/tactics/TA0001/
-
Technique:
- Name: Phishing
- ID: T1566
- Reference URL: https://attack.mitre.org/techniques/T1566/
-
Sub-technique:
- Name: Spearphishing Attachment
- ID: T1566.001
- Reference URL: https://attack.mitre.org/techniques/T1566/001/
-
Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
-
Technique:
- Name: Office Application Startup
- ID: T1137
- Reference URL: https://attack.mitre.org/techniques/T1137/
-
Sub-technique:
- Name: Add-ins
- ID: T1137.006
- Reference URL: https://attack.mitre.org/techniques/T1137/006/