Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9de5b55f9759244…

MALICIOUS

PDF

104.7 KB
MD5: 01f04b446af212a1c110ded577222bce SHA-1: d372dc59d5d32c8a792a817d812422ced37e5260 SHA-256: b9de5b55f975924457f1cc1dd43645016d8326fda8bf5cb045c6325539a0e575
228 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 PowerShell T1105 Ingress Tool Transfer

The PDF file contains embedded content and utilizes XFA forms with risky executable scripts, as indicated by multiple high-severity heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent. The primary attack vector appears to be exploiting a PDF vulnerability to deliver a secondary payload, likely executed from the embedded file 'embedded_file_obj0008.bin'.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • 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: Pdf.Exploit.Dropped-78 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-78
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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.
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • 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
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0008.bin
29df3fa0cda85639f3a8203de7ef992b39d8e6ae248f44be79ae1acd0093c864
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xE2 15203 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).