Malicious PDF — malware analysis report

Static analysis result for SHA-256 c93464f70869b27c…

MALICIOUS

PDF

5.0 KB Created: 2011-04-05 23:46:28 Authoring application: bub lob
MD5: 2b14836156d5c6e1a1c2b7b0b5ea8a9f SHA-1: 8d5f639dbe7a582845a48a8e57b3591c1c5b1f93 SHA-256: c93464f70869b27c82cca94b26a741d6d4dc6c7db17341fa4d44f997224304d1
70 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1566.002 Phishing: Spearphishing Attachment

The ML classifier strongly indicates this PDF is malicious. The presence of an embedded script payload (PDF_EMBEDDED_SCRIPT_PAYLOAD) suggests the document is designed to execute malicious code. The embedded JavaScript file, 'stream_001_off00000331.js', is the primary artifact likely responsible for delivering the malicious payload. The XFA form and embedded file heuristics further support the malicious nature of the document.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_001_off00000331.js
02262c5e01d46a6213ff3904872087be26741f6d0948436d5036c4e360424a9f
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x331 13597 bytes