Malicious PDF — malware analysis report

Static analysis result for SHA-256 1644608d922e1185…

MALICIOUS

PDF

31.7 KB
MD5: 2753d4fed9f4c17facbb341ae5225dfc SHA-1: deb5ab8235fd75215c774719c212688ca2ffc9bd SHA-256: 1644608d922e11857a27b3354fd64f3739ee33f4281c0054aa20026d71e69fce
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file is identified as malicious due to high-severity heuristics indicating an XFA form containing executable script and a numeric evaluation stager. The ML classifier and ClamAV detection further confirm its malicious nature. The embedded URL, while seemingly benign, is part of the XFA structure. The script likely acts as a stager to download and execute a secondary payload, a common technique for initial access via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • XFA form contains risky executable script high CVE related PDF_XFA_SCRIPT
    PDF embeds an XFA form whose script block contains exploit, submission/launch, or shell-execution primitives. Ordinary LiveCycle print/update scripts are left as generic XFA/JS signals unless stronger behavior is present.
  • ClamAV: Js.Exploit.HTML-30 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Js.Exploit.HTML-30
  • XFA numeric character-table eval stager high PDF_XFA_NUMERIC_EVAL_STAGER
    PDF XFA initialize script reads numeric form data from rawValue, maps the values through a short character table, and evals the reconstructed stage. This is an exploit-kit staging technique even when the final decoded layer remains encoded.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.xfa.org/schema/xfa-template/2.5/