Malicious PDF — malware analysis report

Static analysis result for SHA-256 a97d7919a10cd474…

MALICIOUS

PDF

4.7 KB Authoring application: zsrb
MD5: d3a76b1d180efed687feb17813855843 SHA-1: b6ec3152d4b0a45e5774cd2042cc4bd65f8a1a7b SHA-256: a97d7919a10cd474ac3a8f6510cc81ab676e43ede12ac4152de67e2a7fa49acd
72 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by an ML classifier with high confidence. It contains an embedded JavaScript file, indicated by the 'PDF_EMBEDDED_SCRIPT_PAYLOAD' heuristic. This embedded script is the primary indicator of malicious activity, likely serving as a downloader or exploit loader. The 'ML_NYX_PDF_MALICIOUS' heuristic further supports the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • 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
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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
stream_001_off000002b4.js
8812636ec57908c9c472e48ea4c72c3fb3a9576a4e2a0653cacefe9c0a493d8b
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x2B4 41998 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).