Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf1131a9faec8d00…

MALICIOUS

PDF

9.5 KB
MD5: 1b3ccbec18512b4753aaf3a4502704b9 SHA-1: c737f08cdcf1d24d29a09ed67b0271ef0038d5c6 SHA-256: bf1131a9faec8d0088c207012b004fa9adc6decfdd81b0d6eb53350d2ca2cd56
156 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF utilizes XFA forms and embedded JavaScript, indicated by PDF_XFA and PDF_XFA_SCRIPT heuristics. The ML classifier strongly flags it as malicious. The deobfuscated.js script is likely responsible for executing a second-stage payload, as suggested by the 'Script obfuscation indicators' triage signal. The embedded file artifact further supports the payload delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • 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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin
f8c914607a3292f7c685f2804cd63c3732d601b4ee7f4cfe92774caa0ef592a6
pdf-embedded-file PDF EmbeddedFile object 41 at offset 0x52 1164 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
deobfuscated.js
d80eb60e0811a28cb08cb76ecf5787881ab0ef9c0441bbec33049b8acf54965d
deobfuscated-js PDF JavaScript deobfuscation pass 2347 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).