Cscript.exe

Binary used to execute scripts in Windows

Paths

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

Commands

ADS

Use cscript.exe to exectute a Visual Basic script stored in an Alternate Data Stream (ADS).

Use case: Can be used to evade defensive countermeasures or to hide as a persistence mechanism

Privileges: User

cscript //e:vbscript {PATH_ABSOLUTE}:script.vbs

Detection

• Sigma: https://github.com/SigmaHQ/sigma/blob/62d4fd26b05f4d81973e7c8e80d7c1a0c6a29d0e/rules/windows/process_creation/proc_creation_win_wscript_cscript_script_exec.yml
• Sigma: https://github.com/SigmaHQ/sigma/blob/6312dd1d44d309608552105c334948f793e89f48/rules/windows/file/file_event/file_event_win_net_cli_artefact.yml
• Elastic: https://github.com/elastic/detection-rules/blob/61afb1c1c0c3f50637b1bb194f3e6fb09f476e50/rules/windows/defense_evasion_unusual_dir_ads.toml
• Elastic: https://github.com/elastic/detection-rules/blob/cc241c0b5ec590d76cb88ec638d3cc37f68b5d50/rules/windows/command_and_control_remote_file_copy_scripts.toml
• Elastic: https://github.com/elastic/detection-rules/blob/82ec6ac1eeb62a1383792719a1943b551264ed16/rules/windows/defense_evasion_suspicious_managedcode_host_process.toml
• Splunk: https://github.com/splunk/security_content/blob/a1afa0fa605639cbef7d528dec46ce7c8112194a/detections/endpoint/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: Cscript.exe executing files from alternate data streams
• IOC: DotNet CLR libraries loaded into cscript.exe
• IOC: DotNet CLR Usage Log - cscript.exe.log

Resources

• https://gist.github.com/api0cradle/cdd2d0d0ec9abb686f0e89306e277b8f
• https://oddvar.moe/2018/01/14/putting-data-in-alternate-data-streams-and-how-to-execute-it/