Malicious PDF — malware analysis report

Static analysis result for SHA-256 329b3e61a66e1290…

MALICIOUS

PDF

12.0 KB
MD5: 2330155e393934d63627847c97852245 SHA-1: c3f0d552d6e1ed7345ff13152fa350a0449a95a8 SHA-256: 329b3e61a66e12907ec50e5cf5e94fb1b73f029f2d1443362b0fb4274bd8765e
130 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1566.002 Spearphishing Attachment

The PDF was flagged as malicious by a machine learning classifier with a score of 0.999985 and also detected by ClamAV as 'Pdf.Exploit.Dropped-90'. The presence of ASCIIHexDecode filters with exploit indicators and an embedded file further support its malicious nature. The exact attack vector is unclear due to the lack of document body text and scripts, but it is likely a delivery mechanism for a secondary exploit or payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • ClamAV: Pdf.Exploit.Dropped-90 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-90
  • 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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PSSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0001.bin
7a1c44613a025de004d6ffa19ca0cb29a0be25171b8decc12381515d8e1d28ae
pdf-embedded-file PDF EmbeddedFile object 1 at offset 0x5A 1874 bytes