Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bdade04a0572357…

MALICIOUS

PDF

15.2 KB Created: 2011-03-24 18:16:16 Authoring application: hao hup
MD5: a06708390f377e1969efa2a989f1db7a SHA-1: 0a558c57c7da28d011ca656fb6dc6fb4bba28049 SHA-256: 4bdade04a0572357641a7e12602e6fcbfd34244b420964f7c2b08ba4c582974f
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1071.001 Web Protocols

The PDF sample contains multiple high-severity heuristics indicating the presence of executable content and embedded scripts. Specifically, PDF_EVAL and PDF_UNESCAPE point to JavaScript execution, and PDF_EMBEDDED_SCRIPT_PAYLOAD confirms a script payload. The ML classifier strongly flags this as malicious. The embedded script likely attempts to download and execute a secondary payload, as suggested by the embedded file artifact.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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.
  • 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
  • ASCII85Decode filter (with exploit indicators) low PDF_FILTER_85
    ASCII85 encoding filter present alongside exploit delivery indicators — uncommon outside of obfuscation
  • 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 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0012.bin
d81baa73e490e4cb879e13927cacd1dd1be37524a37eac51603e15117c578777
pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x1D74 84 bytes
embedded_file_obj0003.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0
pdf-embedded-file PDF EmbeddedFile object 3 at offset 0x1E25 228 bytes
embedded_file_obj0002.bin
c97e0522381d6196cc0695f35f4d065f15c9c86a9601a7f776c6afd3f4c6b460
pdf-embedded-file PDF EmbeddedFile object 2 at offset 0x1F15 199 bytes
embedded_file_obj0015.bin
9caaaddd68a9e1dc9d09edcb0bbe32d095e3156b48fa5780488f6c23c18222fd
pdf-embedded-file PDF EmbeddedFile object 15 at offset 0x2007 154 bytes
embedded_file_obj0004.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876
pdf-embedded-file PDF EmbeddedFile object 4 at offset 0x20D8 77 bytes
embedded_file_obj0013.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a
pdf-embedded-file PDF EmbeddedFile object 13 at offset 0x217F 56 bytes
embedded_file_obj0010.bin
9f066fceafe479f7226961585c23140e0182484561313604cf981b5bdc42693d
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0x24FD 20590 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).