Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8caabf12e4ab793…

MALICIOUS

PDF

4.9 KB Created: 2011-04-05 23:46:28 Authoring application: bub lob
MD5: 2c563ec98830281d926e0fc48fda24f9 SHA-1: f72ea20d708fe93094cd3d8bfa9b68da7dc5185a SHA-256: b8caabf12e4ab7937e0943a0fef2be1dc5e2b3f6a37c31299fcf7e70c0669e95
70 Risk Score

Malware Insights

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

The PDF file contains an embedded script payload, identified by the 'PDF_EMBEDDED_SCRIPT_PAYLOAD' heuristic. The ML classifier also flagged this PDF as malicious with a high probability. The embedded artifact is a JavaScript file, which is likely responsible for executing the malicious payload. The exact nature of the script's execution is not fully detailed, but its presence strongly indicates a malicious intent, likely to download and execute further stages or exploit vulnerabilities.

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
28043fae0f4e89a30388379e4340ef72e7adc73a08cfe7a910593aede95ca52a
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x331 13561 bytes