Malicious PDF — malware analysis report

Static analysis result for SHA-256 c750a485e40128fe…

MALICIOUS

PDF

104.8 KB
MD5: c280ef82e081a8bf9386476bad56da65 SHA-1: faae4dad2b93df1da7976542b48c5c20013537cc SHA-256: c750a485e40128fe575782d9c1b6f258ed4b61e199b53d36a4193fa76cd30dcb
228 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ClamAV with the signature Pdf.Exploit.Dropped-78. High severity heuristics indicate the presence of unescaped content, embedded script payloads, and risky executable scripts within an XFA form. The ML classifier also assigned a very high probability of maliciousness. These factors suggest the PDF is designed to exploit vulnerabilities and deliver a secondary payload.

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
b4bd4b3a7f74114a3da0d4927f5840040f744bcc1bebf7ab63bf138f4c73e383
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xE2 15227 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).