Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b58c91ed9e6274c…

MALICIOUS

PDF

272.0 KB
MD5: f088fec08373c938b2330f322e47e5db SHA-1: c03632ecd284ec2e2053bc7ec03cc561a7155cfc SHA-256: 3b58c91ed9e6274c7301b26ebf89194db6ea967464613a1f0397aa6cd6b3b280
114 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript

The PDF contains encrypted content and uses JavaScript functions like eval() and unescape(), indicating an attempt to obfuscate malicious code. The ML classifier also flagged this PDF as malicious. While the exact payload is hidden due to encryption and obfuscation, the techniques used suggest it's designed to download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6270

Heuristics 4

  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits
  • Encrypted PDF (string and stream contents are opaque to static scan) info PDF_ENCRYPTED
    PDF declares /Encrypt — string objects and stream contents are encrypted with the standard security handler (RC4 or AES). On its own this is informational; legitimate encrypted documents include signed contracts, billing statements, and rights-managed material. Static heuristics cannot inspect encrypted payload bytes.
  • PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE
    PDF has 2 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.