A compiled HTML help file wrote a script file to the disk

Cortex XDR Analytics Alert Reference by Alert name

Cortex XDR
Last date published
Analytics Alert Reference
Alert name


Activation Period

14 Days

Training Period

30 Days

Test Period

N/A (single event)

Deduplication Period

1 Day

Required Data

  • Requires:
    • XDR Agent
  • Requires:
    • eXtended Threat Hunting (XTH)

Detection Modules

ATT&CK Tactic

Defense Evasion (TA0005)

ATT&CK Technique

System Binary Proxy Execution: Compiled HTML File (T1218.001)




A compiled HTML help file wrote a script file to the disk. Compiled HTLM help files usually don't write script files to the disk. This behavior is often employed by malware that leverage malicious CHM files to deliver a 2nd stage payload.

Attacker's Goals

Deliver a 2nd stage payload or to avoid detection.

Investigative actions

  • Check whether the initiator process is benign or normal for the host and/or user performing it.
  • Check the file that was written to the disk for malicious activities.